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12
Benchmarking Working Group M. Kaeo
Internet-Draft Double Shot Security
Expires: January 9, 2008 T. Van Herck
Cisco Systems
M. Bustos
IXIA
July 8, 2007
Terminology for Benchmarking IPsec Devices
draft-ietf-bmwg-ipsec-term-09
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Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
This purpose of this document is to define terminology specific to
measuring the performance of IPsec devices. It builds upon the
tenets set forth in [RFC1242], [RFC2544], [RFC2285] and other IETF
Benchmarking Methodology Working Group (BMWG) documents used for
benchmarking routers and switches. This document seeks to extend
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these efforts specific to the IPsec paradigm. The BMWG produces two
major classes of documents: Benchmarking Terminology documents and
Benchmarking Methodology documents. The Terminology documents
present the benchmarks and other related terms. The Methodology
documents define the procedures required to collect the benchmarks
cited in the corresponding Terminology documents.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Document Scope . . . . . . . . . . . . . . . . . . . . . . . . 5
3. IPsec Fundamentals . . . . . . . . . . . . . . . . . . . . . . 6
3.1. IPsec Operation . . . . . . . . . . . . . . . . . . . . . 7
3.1.1. Security Associations . . . . . . . . . . . . . . . . 7
3.1.2. Key Management . . . . . . . . . . . . . . . . . . . . 8
4. Definition Format . . . . . . . . . . . . . . . . . . . . . . 10
5. Key Words to Reflect Requirements . . . . . . . . . . . . . . 10
6. Existing Benchmark Definitions . . . . . . . . . . . . . . . . 11
7. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.1. IPsec . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.2. ISAKMP . . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.3. IKE . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.3.1. IKE Phase 1 . . . . . . . . . . . . . . . . . . . . . 13
7.3.2. IKE Phase 1 Main Mode . . . . . . . . . . . . . . . . 13
7.3.3. IKE Phase 1 Aggressive Mode . . . . . . . . . . . . . 13
7.3.4. IKE Phase 2 . . . . . . . . . . . . . . . . . . . . . 14
7.3.5. Phase 2 Quick Mode . . . . . . . . . . . . . . . . . . 14
7.4. Security Association (SA) . . . . . . . . . . . . . . . . 15
7.5. Selectors . . . . . . . . . . . . . . . . . . . . . . . . 15
7.6. IPsec Device . . . . . . . . . . . . . . . . . . . . . . . 15
7.6.1. Initiator . . . . . . . . . . . . . . . . . . . . . . 16
7.6.2. Responder . . . . . . . . . . . . . . . . . . . . . . 17
7.6.3. IPsec Client . . . . . . . . . . . . . . . . . . . . . 17
7.6.4. IPsec Server . . . . . . . . . . . . . . . . . . . . . 17
7.7. Tunnels . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.7.1. IPsec Tunnel . . . . . . . . . . . . . . . . . . . . . 18
7.7.2. Configured Tunnel . . . . . . . . . . . . . . . . . . 18
7.7.3. Established Tunnel . . . . . . . . . . . . . . . . . . 19
7.7.4. Active Tunnel . . . . . . . . . . . . . . . . . . . . 19
7.8. Iterated Tunnels . . . . . . . . . . . . . . . . . . . . . 20
7.8.1. Nested Tunnels . . . . . . . . . . . . . . . . . . . . 20
7.8.2. Transport Adjacency . . . . . . . . . . . . . . . . . 21
7.9. Transform protocols . . . . . . . . . . . . . . . . . . . 21
7.9.1. Authentication Protocols . . . . . . . . . . . . . . . 22
7.9.2. Encryption Protocols . . . . . . . . . . . . . . . . . 22
7.10. IPsec Protocols . . . . . . . . . . . . . . . . . . . . . 23
7.10.1. Authentication Header (AH) . . . . . . . . . . . . . . 23
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7.10.2. Encapsulated Security Payload (ESP) . . . . . . . . . 24
7.11. NAT Traversal (NAT-T) . . . . . . . . . . . . . . . . . . 25
7.12. IP Compression . . . . . . . . . . . . . . . . . . . . . . 25
7.13. Security Context . . . . . . . . . . . . . . . . . . . . . 26
8. Framesizes . . . . . . . . . . . . . . . . . . . . . . . . . . 28
8.1. Layer3 clear framesize . . . . . . . . . . . . . . . . . . 28
8.2. Layer3 encrypted framesize . . . . . . . . . . . . . . . . 29
9. Performance Metrics . . . . . . . . . . . . . . . . . . . . . 30
9.1. IPsec Tunnels Per Second (TPS) . . . . . . . . . . . . . . 30
9.2. Tunnel Rekeys Per Seconds (TRPS) . . . . . . . . . . . . . 30
9.3. IPsec Tunnel Attempts Per Second (TAPS) . . . . . . . . . 31
10. Test Definitions . . . . . . . . . . . . . . . . . . . . . . . 31
10.1. Capacity . . . . . . . . . . . . . . . . . . . . . . . . . 31
10.1.1. IKE SA Capacity . . . . . . . . . . . . . . . . . . . 31
10.1.2. IPsec SA Capacity . . . . . . . . . . . . . . . . . . 32
10.2. Throughput . . . . . . . . . . . . . . . . . . . . . . . . 32
10.2.1. IPsec Throughput . . . . . . . . . . . . . . . . . . . 32
10.2.2. IPsec Encryption Throughput . . . . . . . . . . . . . 33
10.2.3. IPsec Decryption Throughput . . . . . . . . . . . . . 34
10.3. Latency . . . . . . . . . . . . . . . . . . . . . . . . . 34
10.3.1. IPsec Latency . . . . . . . . . . . . . . . . . . . . 34
10.3.2. IPsec Encryption Latency . . . . . . . . . . . . . . . 35
10.3.3. IPsec Decryption Latency . . . . . . . . . . . . . . . 35
10.3.4. Time To First Packet . . . . . . . . . . . . . . . . . 36
10.4. Frame Loss . . . . . . . . . . . . . . . . . . . . . . . . 37
10.4.1. IPsec Frame Loss . . . . . . . . . . . . . . . . . . . 37
10.4.2. IPsec Encryption Frame Loss . . . . . . . . . . . . . 37
10.4.3. IPsec Decryption Frame Loss . . . . . . . . . . . . . 37
10.4.4. IKE Phase 2 Rekey Frame Loss . . . . . . . . . . . . . 38
10.5. Back-to-back Frames . . . . . . . . . . . . . . . . . . . 38
10.5.1. IPsec Back-to-back Frames . . . . . . . . . . . . . . 38
10.5.2. IPsec Encryption Back-to-back Frames . . . . . . . . . 39
10.5.3. IPsec Decryption Back-to-back Frames . . . . . . . . . 39
10.6. Tunnel Setup Behavior . . . . . . . . . . . . . . . . . . 40
10.6.1. IPsec Tunnel Setup Rate . . . . . . . . . . . . . . . 40
10.6.2. IKE Phase 1 Setup Rate . . . . . . . . . . . . . . . . 40
10.6.3. IKE Phase 2 Setup Rate . . . . . . . . . . . . . . . . 41
10.7. IPsec Tunnel Rekey Behavior . . . . . . . . . . . . . . . 41
10.7.1. IKE Phase 1 Rekey Rate . . . . . . . . . . . . . . . . 41
10.7.2. IKE Phase 2 Rekey Rate . . . . . . . . . . . . . . . . 42
10.8. IPsec Tunnel Failover Time . . . . . . . . . . . . . . . . 42
10.9. DoS Attack Resiliency . . . . . . . . . . . . . . . . . . 43
10.9.1. Phase 1 DoS Resiliency Rate . . . . . . . . . . . . . 43
10.9.2. Phase 2 DoS Resiliency Rate . . . . . . . . . . . . . 43
11. Security Considerations . . . . . . . . . . . . . . . . . . . 44
12. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 44
13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 44
13.1. Normative References . . . . . . . . . . . . . . . . . . . 44
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13.2. Informative References . . . . . . . . . . . . . . . . . . 47
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 47
Intellectual Property and Copyright Statements . . . . . . . . . . 48
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1. Introduction
Despite the need to secure communications over a public medium there
is no standard method of performance measurement nor a standard in
the terminology used to develop such hardware and software solutions.
This results in varied implementations which challenge
interoperability and direct performance comparisons. Standardized
IPsec terminology and performance test methodologies will enable
users to determine if the IPsec device they select will withstand
loads of secured traffic that meet their requirements.
To appropriately define the parameters and scope of this document,
this section will give a brief overview of the IPsec standard:
2. Document Scope
The primary focus of this document is to establish useful performance
testing terminology for IPsec devices that support manual keying and
IKEv1. We want to constrain the terminology specified in this
document to meet the requirements of the Methodology for Benchmarking
IPsec Devices documented test methodologies.
Both IPv4 and IPv6 addressing will be taken into consideration.
The testing will be constrained to:
o Devices acting as IPsec gateways whose tests will pertain to both
IPsec tunnel and transport mode.
o Devices acting as IPsec end-hosts whose tests will pertain to both
IPsec tunnel and transport mode.
Any testing involving interoperability and/or conformance issues,
L2TP [RFC2661], GRE [RFC2784], MPLS VPN's [RFC2547], multicast, and
anything that does not specifically relate to the establishment and
tearing down of IPsec tunnels is specifically out of scope. It is
assumed that all relevant networking parameters that facilitate in
the running of these tests are pre-configured (this includes at a
minimum ARP caches, routing tables, neighbor tables, etc ...).
A separate document will be written specifically to address testing
using the updated IKEv2 specification. Due to the dependency on
IKEv2 of the updated IPsec architecture document [RFC4301], this
document and the companion IPsec Benchmarking Methodology document
will be based on the older IPsec architecture standard [RFC2401].
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3. IPsec Fundamentals
IPsec is a framework of open standards that provides data
confidentiality, data integrity, and data origin authenticity between
participating peers. IPsec provides these security services at the
IP layer. IPsec uses IKE to handle negotiation of protocols and
algorithms based on local policy, and to generate the encryption and
authentication keys to be used. IPsec can be used to protect one or
more data flows between a pair of hosts, between a pair of security
gateways, or between a security gateway and a host. The IPsec
protocol suite set of standards is documented in RFC's [RFC2401]
through [RFC2412] and [RFC2451]. At this time [RFC4301] updates
[RFC2401] (IPsec Architecture), [RFC4302] updates [RFC2402] (AH) and
[RFC4303] updates [RFC2406] (ESP) and [RFC4306] updates [RFC2409]
(IKE).The reader is assumed to be familiar with these documents.
IPsec itself defines the following:
Authentication Header (AH): A security protocol, defined in
[RFC4302], which provides data authentication and optional anti-
replay services. AH ensures the integrity and data origin
authentication of the IP datagram as well as the invariant fields in
the outer IP header.
Encapsulating Security Payload (ESP): A security protocol, defined in
[RFC4303], which provides confidentiality, data origin
authentication, connectionless integrity, an anti-replay service and
limited traffic flow confidentiality. The set of services provided
depends on options selected at the time of Security Association (SA)
establishment and on the location of the implementation in a network
topology. ESP authenticates only headers and data after the IP
header.
Internet Key Exchange (IKE): A hybrid protocol which implements
Oakley [RFC2412] and SKEME [SKEME] key exchanges inside the ISAKMP
framework. While IKE can be used with other protocols, its initial
implementation is with the IPsec protocol. IKE provides
authentication of the IPsec peers, negotiates IPsec security
associations, and establishes IPsec keys.
The AH and ESP protocols each support two modes of operation:
transport mode and tunnel mode. In transport mode, two hosts provide
protection primarily for upper-layer protocols. The cryptographic
endpoints (where the encryption and decryption take place) are the
source and destination of the data packet. In IPv4, a transport mode
security protocol header appears immediately after the IP header and
before any higher-layer protocols (such as TCP or UDP). In IPv6, the
security protocol header appears after the base IP header and
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selected extension headers. It may appear before or after
destination options but must appear before next layer protocols
(e.g., TCP, UDP, SCTP)
In the case of AH in transport mode, security services are provided
to selected portions of the IP header preceding the AH header,
selected portions of extension headers, and selected options
(contained in the IPv4 header, IPv6 Hop-by-Hop extension header, or
IPv6 Destination extension headers). Any fields in these headers/
extension headers which are modified in transit are set to 0 before
applying the authentication algorithm. If a field is mutable, but
its value at the receiving IPsec peer is predictable, then that value
is inserted into the field before applying the cryptographic
algorithm.
In the case of ESP in transport mode, security services are provide
only for the higher-layer protocols, not for the IP header or any
extension headers preceding the ESP header.
A tunnel is a vehicle for encapsulating packets inside a protocol
that is understood at the entry and exit points of a given network.
These entry and exit points are defined as tunnel interfaces.
Both the AH and ESP protocols can be used in tunnel mode for data
packet endpoints as well as by intermediate security gateways. In
tunnel mode, there is an "outer" IP header that specifies the IPsec
processing destination, plus an "inner" IP header that specifies the
ultimate destination for the packet. The source address in the outer
IP header is the initiating cryptographic endpoint; the source
address in the inner header is the true source address of the packet.
The security protocol header appears after the outer IP header and
before the inner IP header.
If AH is employed in tunnel mode, portions of the new outer IP header
are given protection (those same fields as for transport mode,
described earlier in this section), as well as all of the tunneled IP
packet (that is, all of the inner IP header is protected as are the
higher-layer protocols). If ESP is employed, the protection is
afforded only to the tunneled packet, not to the new outer IP header.
3.1. IPsec Operation
3.1.1. Security Associations
The concept of a Security Association (SA) is fundamental to IPsec.
An SA is a relationship between two or more entities that describes
how the entities will use security services to communicate. The SA
includes: an encryption algorithm, an authentication algorithm and a
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shared session key.
Because an SA is unidirectional, two SA's (one in each direction) are
required to secure typical, bidirectional communication between two
entities. The security services associated with an SA can be used
for AH or ESP, but not for both. If both AH and ESP protection is
applied to a traffic stream, two (or more) SA's are created for each
direction to protect the traffic stream.
The SA is uniquely identified by the Security Parameter Index (SPI)
[RFC2406]. When a system sends a packet that requires IPsec
protection, it looks up the SA in its database and applies the
specified processing and security protocol (AH/ESP), inserting the
SPI from the SA into the IPsec header. When the IPsec peer receives
the packet, it looks up the SA in its database by destination
address, protocol, and SPI and then processes the packet as required.
3.1.2. Key Management
IPsec uses cryptographic keys for authentication, integrity and
encryption services. Both manual provisioning and automatic
distribution of keys is supported. IKE is specified as the public-
key-based approach for automatic key management.
IKE authenticates each peer involved in IPsec, negotiates the
security policy, and handles the exchange of session keys. IKE is a
hybrid protocol, combining parts of the following protocols to
negotiate and derive keying material for SA's in a secure and
authenticated manner:
1. ISAKMP [RFC2408] (Internet Security Association and Key
Management Protocol), which provides a framework for
authentication and key exchange but does not define them. ISAKMP
is designed to be key exchange independent; it is designed to
support many different key exchanges.
2. Oakley [RFC2412], which describes a series of key exchanges,
called modes, and details the services provided by each (for
example, perfect forward secrecy for keys, identity protection,
and authentication).
3. [SKEME] (Secure Key Exchange Mechanism for Internet), which
describes a versatile key exchange technique that provides
anonymity, reputability, and quick key refreshment.
IKE creates an authenticated, secure tunnel between two entities and
then negotiates the security association for IPsec. In the original
IKE specification [RFC2409], this is performed in two phases.
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In Phase 1, the two unidirectional SA's establish a secure,
authenticated channel with which to communicate. Phase 1 has two
distinct modes; Main Mode and Aggressive Mode. Main Mode for Phase 1
provides identity protection. When identity protection is not
needed, Aggressive Mode can be used. The completion of Phase 1 is
called an IKE SA.
The following attributes are used by IKE and are negotiated as part
of the IKE SA:
o Encryption algorithm.
o Hash algorithm.
o Authentication method (digital signature, public-key encryption or
pre-shared key).
o Diffie-Hellman group information.
After the attributes are negotiated, both parties must be
authenticated to each other. IKE supports multiple authentication
methods. The following mechanisms are generally implemented:
o Pre-shared keys: The same key is pre-installed on each host. IKE
peers authenticate each other by computing and sending a keyed
hash of data that includes the pre-shared key. If the receiving
peer can independently create the same hash using its preshared
key, it knows that both parties must share the same secret, and
thus the other party is authenticated.
o Public key cryptography: Each party generates a pseudo-random
number (a nonce) and encrypts it and its ID using the other
party's public key. The ability for each party to compute a keyed
hash containing the other peer's nonce and ID, decrypted with the
local private key, authenticates the parties to each other. This
method does not provide nonrepudiation; either side of the
exchange could plausibly deny that it took part in the exchange.
o Digital signature: Each device digitally signs a set of data and
sends it to the other party. This method is similar to the
public-key cryptography approach except that it provides
nonrepudiation.
Note that both digital signature and public-key cryptography require
the use of digital certificates to validate the public/private key
mapping. IKE allows the certificate to be accessed independently or
by having the two devices explicitly exchange certificates as part of
IKE. Both parties must have a shared session key to encrypt the IKE
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tunnel. The Diffie-Hellman protocol is used to agree on a common
session key.
In Phase 2 of IKE, SA's are negotiated for ESP and/or AH. These SA's
will be called IPsec SA's. These IPsec SA's use a different shared
key than that used for the IKE_SA. The IPsec SA shared key can be
derived by using Diffie-Hellman again or by refreshing the shared key
derived from the original Diffie-Hellman exchange that generated the
IKE_SA by hashing it with nonces. Once the shared key is derived and
additional communication parameters are negotiated, the IPsec SA's
are established and traffic can be exchanged using the negotiated
parameters.
4. Definition Format
The definition format utilized by this document is described in
[RFC1242], Section 2.
Term to be defined.
Definition: The specific definition for the term.
Discussion: A brief discussion of the term, its application, or
other information that would build understanding.
Issues: List of issues or conditions that affect this term. This
field can present items the may impact the term's related
methodology or otherwise restrict its measurement procedures.
[Measurement units:] Units used to record measurements of this term.
This field is mandatory where applicable. This field is optional
in this document.
[See Also:] List of other terms that are relevant to the discussion
of this term. This field is optional in this document.
5. Key Words to Reflect Requirements
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119. RFC 2119
defines the use of these key words to help make the intent of
standards track documents as clear as possible. While this document
uses these keywords, this document is not a standards track document.
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6. Existing Benchmark Definitions
It is recommended that readers consult [RFC1242], [RFC2544] and
[RFC2285] before making use of this document. These and other IETF
Benchmarking Methodology Working Group (BMWG) router and switch
documents contain several existing terms relevant to benchmarking the
performance of IPsec devices. The conceptual framework established
in these earlier RFC's will be evident in this document.
This document also draws on existing terminology defined in other
BMWG documents. Examples include, but are not limited to:
Throughput [RFC 1242, section 3.17]
Latency [RFC 1242, section 3.8]
Frame Loss Rate [RFC 1242, section 3.6]
Forwarding Rates [RFC 2285, section 3.6]
Loads [RFC 2285, section 3.5]
7. Definitions
7.1. IPsec
Definition: IPsec or IP Security protocol suite which comprises a
set of standards used to provide security services at the IP
layer.
Discussion: IPsec is a framework of protocols that offer
authentication, integrity and encryption services to the IP and/or
upper layer protocols. The major components of the protocol suite
are IKE, used for key exchanges, and IPsec protocols such as AH
and ESP, which use the exchanged keys to protect payload traffic.
Issues: N/A
See Also: IPsec Device, IKE, ISAKMP, ESP, AH
7.2. ISAKMP
Definition: The Internet Security Association and Key Management
Protocol, which provides a framework for authentication and key
exchange but does not define them. ISAKMP is designed to be key
exchange independent; it is designed to support many different key
exchanges. ISAKMP is defined in [RFC2407].
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Discussion: Though ISAKMP is only a framework for the IPsec standard
key management protocol, it is often misused and interchanged with
the term 'IKE', which is an implementation of ISAKMP.
Issues: When implementations refer to the term 'ISAKMP SA', it
refers to an IKE Phase 1 SA.
See Also: IKE, Security Association
7.3. IKE
Definition: A hybrid key management protocol that provides
authentication of the IPsec peers, negotiates IPsec SAs and
establishes IPsec keys.
Discussion: A hybrid protocol, defined in [RFC2409], from the
following 3 protocols:
* ISAKMP (Internet Security Association and Key Management
Protocol), which provides a framework for authentication and
key exchange but does not define them. ISAKMP is designed to
be key exchange independent; it is designed to support many
different key exchanges.
* Oakley, which describes a series of key exchanges, called
modes, and details the services provided by each (for example,
perfect forward secrecy for keys, identity protection, and
authentication). [RFC2412]
* [SKEME] (Secure Key Exchange Mechanism for Internet), which
describes a versatile key exchange technique that provides
anonymity, reputability, and quick key refreshment.
Note that IKE is an optional protocol within the IPsec framework.
IPsec SAs may also be manually configured. Manual keying is the
most basic mechanism to establish IPsec SAs between two IPsec
devices. However, it is not a scalable solution and often
manually configured keys are not changed on a periodic basis which
reduces the level of protection since the keys are effectively
static and as a result are more prone to various attacks. When
IKE is employed as a key management protocol, the keys are
automatically renegotiated on a user-defined basis (time and/or
traffic volume based) as part of the IKE rekeying mechanism.
Issues: During the first IPsec deployment experiences, ambiguities
were found in the IKEv1 specification, which lead to
interoperability problems. To resolve these issues, IKEv1 is
being updated by IKEv2.
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See Also: ISAKMP, IPsec, Security Association
7.3.1. IKE Phase 1
Definition: The shared policy and key(s) used by negotiating peers
to establish a secure authenticated "control channel" for further
IKE communications.
Discussion: The IPsec framework mandates that SPI's are used to
secure payload traffic. If IKE is employed all SPI information
will be exchanged between the IPsec devices. This has to be done
in a secure fashion and for that reason IKE will set up a secure
"control channel" over which it can exchange this information.
Note that IKE is an optional protocol within the IPsec framework
and that SPI information can also be manually configured.
Issues: In some documents often referenced as ISAKMP SA or IKE SA.
See Also: IKE, ISAKMP
7.3.2. IKE Phase 1 Main Mode
Definition: Main Mode is an instantiation of the ISAKMP Identity
Protect Exchange, defined in [RFC2409]. Upon successful
completion it results in the establishment of an IKE Phase 1 SA.
Discussion: IKE Main Mode use 3 distinct message pairs, for a total
of 6 messages. The first two messages negotiate policy; the next
two represent Diffie-Hellman public values and ancillary data
(e.g. nonces); and the last two messages authenticate the Diffie-
Hellman Exchange. The authentication method negotiated as part of
the initial IKE Phase 1 influence the composition of the payloads
but not their purpose.
Issues: N/A
See Also: ISAKMP, IKE, IKE Phase 1, Phase 1 Aggressive Mode
7.3.3. IKE Phase 1 Aggressive Mode
Definition: Aggressive Mode is an instantiation of the ISAKMP
Aggressive Exchange, defined in [RFC2409]. Upon successful
completion it results in the establishment of an IKE Phase 1 SA.
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Discussion: IKE Aggressive Mode uses 3 messages. The first two
messages negotiate policy, exchange Diffie-Hellman public values
and ancillary data necessary for the exchange, and identities. In
addition the second message authenticates the Responder. The
third message authenticates the Initiator and provides proof of
participation in the exchange.
Issues: For IKEv1 the standard specifies that all implementations
use both main and agressive mode, however, it is common to use
only main mode.
See Also: ISAKMP, IKE, IKE Phase 1, Phase 1 Main Mode
7.3.4. IKE Phase 2
Definition: ISAKMP phase which upon successful completion
establishes the shared keys used by the negotiating peers to set
up a secure "data channel" for IPsec.
Discussion: The main purpose of Phase 2 is to produce the key for
the IPsec tunnel. Phase 2 is also used for exchanging
informational messages.
Issues: In other documents also referenced as IPsec SA.
See Also: IKE Phase 1, ISAKMP, IKE
7.3.5. Phase 2 Quick Mode
Definition: Quick Mode is an instanciation of IKE Phase 2. After
successful completion it will result in one or typically two or
more IPsec SA's
Discussion: Quick Mode is used to negotiate the SA's and keys that
will be used to protect the user data. Three different messages
are exchanged, which are protected by the security parameters
negotiated by the IKE phase 1 exchange. An additional Diffie-
Hellman exchange may be performed if PFS (Perfect Forward Secrecy)
is enabled.
Issues: N/A
See Also: ISAKMP, IKE, IKE Phase 2
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7.4. Security Association (SA)
Definition: A set of policy and key(s) used to protect traffic flows
that require authentication and/or encryption services. It is a
negotiation agreement between two IPsec devices, specifically the
Initiator and Responder.
Discussion: A simplex (unidirectional) logical connection that links
a traffic flow to a set of security parameters. All traffic
traversing an SA is provided the same security processing and will
be subjected to a common set of encryption and/or authentication
algorithms. In IPsec, an SA is an Internet layer abstraction
implemented through the use of AH or ESP as defined in [RFC2401].
Issues: N/A
See Also: Initiator, Responder
7.5. Selectors
Definition: A mechanism used for the classification of traffic flows
that require authentication and/or encryption services.
Discussion: The selectors are a set of fields that will be extracted
from the network and transport layer headers that provide the
ability to classify the traffic flow and associate it with an SA.
After classification, a decision can be made if the traffic needs
to be encrypted/decrypted and how this should be done depending on
the SA linked to the traffic flow. Simply put, selectors classify
IP packets that require IPsec processing and those packets that
must be passed along without any intervention of the IPsec
framework.
Selectors are flexible objects that can match on ranges of source
and destination addresses and ranges of source and destination
ports.
Issues: Both sides must agree exactly on both the networks being
protected, and they both must agree on how to describe the
networks (range, subnet, addresses). This is a common point of
non-interoperability.
7.6. IPsec Device
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Definition: Any implementation that has the ability to process data
flows according to the IPsec protocol suite specifications.
Discussion: Implementations can be grouped by 'external' properties
(e.g. software vs. hardware implementations) but more important is
the subtle differences that implementations may have with relation
to the IPsec Protocol Suite. Not all implementations will cover
all RFC's that encompass the IPsec Protocol Suite, but the
majority will support a large subset of features described in the
suite, nor will all implementations utilize all of the
cryptographic functions listed in the RFC's.
In that context, any implementation, that supports basic IP layer
security services as described in the IPsec protocol suite shall
be called an IPsec Device.
Issues: Due to the fragmented nature of the IPsec Protocol Suite
RFC's, it is possible that IPsec implementations will not be able
to interoperate. Therefore it is important to know which features
and options are implemented in the IPsec Device.
See Also: IPsec
7.6.1. Initiator
Definition: An IPsec device which starts the negotiation of IKE
Phase 1 and IKE Phase 2 SAs.
Discussion: When a traffic flow is offered at an IPsec device and it
is determined that the flow must be protected, but there is no
IPsec tunnel to send the traffic through, it is the responsibility
of the IPsec device to start a negotiation process that will
instantiate the IPsec tunnel. This process will establish an IKE
Phase 1 SA and one, or more likely, a pair IKE phase 2 SA's,
eventually resulting in secured data transport. The device that
takes the action to start this negotiation process will be called
an Initiator.
Issues: IPsec devices/implementations can be both an initiator as
well as a responder. The distinction is useful from a test
perspective.
See Also: Responder, IKE, IPsec
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7.6.2. Responder
Definition: An IPsec device which replies to incoming IKE Phase 1
and IKE Phase 2 requests and processes these messages in order to
establish an IPsec tunnel.
Discussion: When an initiator attempts to establish SA's with
another IPsec device, this peer will need to evaluate the
proposals made by the initiator and either accept or deny them.
In the former case, the traffic flow will be decrypted according
to the negotiated parameters. Such a device will be called a
Responder.
Issues: IPsec devices/implementations can usually be both an
initiator as well as a responder. The distinction is useful from
a test perspective.
See Also: Initiator, IKE
7.6.3. IPsec Client
Definition: IPsec Devices that will only act as an Initiator.
Discussion: In some situations it is not needed or prefered to have
an IPsec device respond to an inbound IKE SA or IPsec SA request.
In the case of e.g. road warriors or home office scenarios the
only property needed from the IPsec device is the ability to
securely connect to a remote private network. The IPsec Client
will initiate one or more IPsec tunnels to an IPsec Server on the
network that needs to be accessed and to provide the required
security services. An IPsec client will silently drop and ignore
any inbound IPsec tunnel requests. IPsec clients are generally
used to connect remote users in a secure fashion over the Internet
to a private network.
Issues: N/A
See Also: IPsec device, IPsec Server, Initiator, Responder
7.6.4. IPsec Server
Definition: IPsec Devices that can both act as an Initiator as well
as a Responder.
Discussion: IPsec Servers are mostly positioned at private network
edges and provide several functions:
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* Responds to IPsec tunnel setup request from IPsec Clients.
* Responds to IPsec tunnel setup request from other IPsec devices
(Initiators).
* Initiate IPsec tunnels to other IPsec servers inside or outside
the private network.
Issues: IPsec Servers are also sometimes referred to as 'VPN
Concentrators'.
See Also: IPsec Device, IPsec Client, Initiator, Responder
7.7. Tunnels
The term "tunnel" is often used in a variety of contexts. To avoid
any discrepancies, in this document, the following distinctions have
been defined:
7.7.1. IPsec Tunnel
Definition: The combination of an IKE Phase 1 SA and a pair of IKE
Phase 2 SA's.
Discussion: An IPsec Tunnel will be defined as a single (1) Phase 1
SA and a pair (2) Phase 2 SA's. This construct will allow
bidirectional traffic to be passed between two IPsec Devices where
the traffic can benefit form the services offered in the IPsec
framework.
Issues: Since it is implied that a Phase 1 SA is used, an IPsec
Tunnel will be by definition a dynamically negotiated secured
link. If manual keying is used to enable secure data transport,
then this link will merely be referred to as a pair of IPsec SA's.
It is very likely that more then one pair of Phase 2 SA's are
associated with a single Phase 1 SA. Also in this case, the IPsec
Tunnel definition WILL NOT apply. Instead the ratio between Phase
1 SA's and Phase 2 SA's MUST be explictly stated. The umbrella
term of "IPsec Tunnel" MUST NOT be used in this context.
See Also: IKE Phase 1, IKE Phase 2
7.7.2. Configured Tunnel
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Definition: An IPsec tunnel or a pair of IPsec SAs in the case of
manual keying that is provisioned in the IPsec device's
configuration.
Discussion: Several steps are required before IPsec can be used to
actually transport traffic. The very first step is to configure
the IPsec Tunnel (or IPsec SAs in the case of manual keying) in
the IPsec device. When using IKE there are no SA's associated
with the IPsec Tunnel and no traffic is going through the IPsec
device that matches the Selectors, which would instantiate the
IPsec Tunnel. When using either manual keying or IKE, a
configured tunnel will not have a populated SADB.
Issues: When using IKE, a configured tunnel will not have any SA's
while with manual keying, the SAs will have simply been configured
but not populated in the SADB.
See Also: IPsec Tunnel, Established Tunnel, Active Tunnel
7.7.3. Established Tunnel
Definition: An IPsec device that has a populated SADB and is ready
to provide security services to the appropriate traffic.
Discussion: When using IKE, a second step needed to ensure that an
IPsec Tunnel can transport data is to complete the Phase 1 and
Phase 2 negotiations. After the packet classification process has
asserted that a packet requires security services, the negotation
is started to obtain both Phase 1 and Phase 2 SAs. After this is
completed and the SADB is populated, the IPsec Tunnel is called
'Established'. Note that at this time there is still no traffic
flowing through the IPsec Tunnel. Just enough packet(s) have been
sent to the IPsec device that matched the selectors and triggered
the IPsec Tunnel setup to result in a populated SADB. In the case
of manual keying, populating the SADB is accomplished by a
separate administrative command.
Issues: N/A
See Also: IPsec Tunnel, Configured Tunnel, Active Tunnel
7.7.4. Active Tunnel
Definition: An IPsec device that is forwarding secured data.
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Discussion: When a Tunnel is Established and it is transporting
traffic that is authenticated and/or encrypted, the tunnel is
called 'Active'.
Issues: The distinction between an Active Tunnel and Configured/
Established Tunnel is made in the context of manual keyed Tunnels.
In this case it would be possible to have an Established tunnel on
an IPsec device which has no counterpart on it's corresponding
peer. This will lead to encrypted traffic flows which will be
discarded on the receiving peer. Only if both peers have an
Established Tunnel that shows evidence of traffic transport, it
may be called an Active Tunnel.
See Also: IPsec Tunnel, Configured Tunnel, Established Tunnel
7.8. Iterated Tunnels
Iterated Tunnels are a bundle of transport and/or tunnel mode SA's.
The bundles are divided into two major groups :
7.8.1. Nested Tunnels
Definition: An SA bundle consisting of two or more 'tunnel mode'
SA's.
Discussion: The process of nesting tunnels can theoretically be
repeated multiple times (for example, tunnels can be many levels
deep), but for all practical purposes, most implementations limit
the level of nesting. Nested tunnels can use a mix of AH and ESP
encapsulated traffic.
[GW1] --- [GW2] ---- [IP CLOUD] ---- [GW3] --- [GW4]
| | | |
| | | |
| +----{SA1 (ESP tunnel)}----+ |
| |
+--------------{SA2 (AH tunnel)}---------------+
In the IP Cloud a packet would have a format like this :
[IP{2,3}][ESP][IP{1,4}][AH][IP][PAYLOAD][ESP TRAILER][ESP AUTH]
Nested tunnels can be deployed to provide additional security on
already secured traffic. A typical example of this would be that
the inner gateways (GW2 and GW3) are securing traffic between two
branch offices and the outer gateways (GW1 & GW4) add an
additional layer of security between departments within those
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branch offices.
Issues: N/A
See Also: Transport Adjacency, IPsec Tunnel
7.8.2. Transport Adjacency
Definition: An SA bundle consisting of two or more transport mode
SA's.
Discussion: Transport adjacency is a form of tunnel nesting. In
this case two or more transport mode IPsec tunnels are set side by
side to enhance applied security properties.
Transport adjacency can be used with a mix of AH and ESP tunnels
although some combinations are not preferred. If AH and ESP are
mixed, the ESP tunnel should always encapsulate the AH tunnel.
The reverse combination is a valid combination but doesn't make
cryptographical sense.
[GW1] --- [GW2] ---- [IP CLOUD] ---- [GW3] --- [GW4]
| | | |
| | | |
| +------{SA1 (ESP transport)}--------+ |
| |
+-------------{SA2 (AH transport)}--------------+
In the IP Cloud a packet would have a format like this :
[IP][ESP][AH][PAYLOAD][ESP TRAILER][ESP AUTH]
Issues: This is rarely used in the way it is depicted. It is more
common, but still not likely, that SA's are established from
different gateways as depicted in the Nested Tunnels figure. The
packet format in the IP Cloud would remain unchanged.
See Also: Nested Tunnels, IPsec Tunnel
7.9. Transform protocols
Definition: Encryption and authentication algorithms that provide
cryptograhic services to the IPsec Protocols.
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Discussion: Some algorithms run significantly slower than others. A
decision for which algorithm to use is usually based on the
tradeoff between performance and security strength. For example,
3DES encryption is generally slower then DES encryption.
Issues: N/A
See Also: Authentication protocols, Encryption protocols
7.9.1. Authentication Protocols
Definition: Algorithms which provide data integrity and data source
authentication.
Discussion: Authentication protocols provide no confidentiality.
Commonly used authentication algorithms/protocols are:
* MD5-HMAC
* SHA-HMAC
* AES-HMAC
Issues: N/A
See Also: Transform protocols, Encryption protocols
7.9.2. Encryption Protocols
Definition: Algorithms which provide data confidentiality.
Discussion: Encryption protocols provide no authentication.
Commonly used encryption algorithms/protocols are:
* NULL encryption
* DES-CBC
* 3DES-CBC
* AES-CBC
Issues: The null-encryption option is a valid encryption mechanism
to provide an alternative to using AH. There is no
confidentiality protection with null-encryption. Note also that
when using ESP null-encryption the authentication and integrity
services only apply for the upper layer protocols and not for the
IP header itself.
DES has been officially deprecated by NIST, though it is still
mandated by the IPsec framework and is still commonly implemented
and used due to it's speed advantage over 3DES. AES will be the
successor of 3DES due to its superior encryption and performance
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advantage.
See Also: Transform protocols, Authentication protocols
7.10. IPsec Protocols
Definition: A suite of protocols which provide a framework of open
standards that provides data origin confidentiality, data
integrity, and data origin authenticity between participating
peers at the IP layer. The original IPsec protocol suite set of
standards is documented in [RFC2401] through [RFC2412] and
[RFC2451]. At this time [RFC4301] updates [RFC2401] (IPsec
Architecture), [RFC4302] updates [RFC2402] (AH) and [RFC4303]
updates [RFC2406] (ESP)
Discussion: The IPsec Protocol suite is modular and forward
compatible. The protocols that comprise the IPsec protocol suite
can be replaced with new versions of those protocols as the older
versions become obsolete. For example, IKEv2 will soon replace
IKEv1.
Issues: N/A
See Also: AH, ESP
7.10.1. Authentication Header (AH)
Definition: Provides data origin authentication and data integrity
(including replay protection) security services as defined in
[RFC4302].
Discussion: The AH protocol supports two modes of operation i.e.
tunnel mode and transport mode.
In transport mode, AH is inserted after the IP header and before a
next layer protocol, e.g., TCP, UDP, ICMP, etc. or before any
other IPsec headers that have already been inserted. In the
context of IPv4, this calls for placing AH after the IP header
(and any options that it contains), but before the next layer
protocol. In the IPv6 context, AH is viewed as an end-to-end
payload, and thus should appear after hop-by-hop, routing, and
fragmentation extension headers. The destination options
extension header(s) could appear before or after or both before
and after the AH header depending on the semantics desired.
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In tunnel mode, the "inner" IP header carries the ultimate (IP)
source and destination addresses, while an "outer" IP header
contains the addresses of the IPsec "peers," e.g., addresses of
security gateways. In tunnel mode, AH protects the entire inner
IP packet, including the entire inner IP header. The position of
AH in tunnel mode, relative to the outer IP header, is the same as
for AH in transport mode.
Issues: AH is rarely used to secure traffic over the Internet.
See Also: Transform protocols, IPsec protocols, Encapsulated
Security Payload
7.10.2. Encapsulated Security Payload (ESP)
Definition: Provides data origin authentication, data integrity
(including replayprotection) and data confidentiality as defined
in [RFC4303].
Discussion: The ESP protocol supports two modes of operation i.e.
tunnel mode and transport mode.
In transport mode, ESP is inserted after the IP header and before
a next layer protocol, e.g., TCP, UDP, ICMP, etc. In the context
of IPv4, this translates to placing ESP after the IP header (and
any options that it contains), but before the next layer protocol.
In the IPv6 context, ESP is viewed as an end-to-end payload, and
thus should appear after hop-by-hop, routing, and fragmentation
extension headers. Destination options extension header(s) could
appear before, after, or both before and after the ESP header
depending on the semantics desired. However, since ESP protects
only fields after the ESP header, it generally will be desirable
to place the destination options header(s) after the ESP header.
In tunnel mode, the "inner" IP header carries the ultimate (IP)
source and destination addresses, while an "outer" IP header
contains the addresses of the IPsec "peers", e.g., addresses of
security gateways. Mixed inner and outer IP versions are allowed,
i.e., IPv6 over IPv4 and IPv4 over IPv6. In tunnel mode, ESP
protects the entire inner IP packet, including the entire inner IP
header. The position of ESP in tunnel mode, relative to the outer
IP header, is the same as for ESP in transport mode.
Issues: N/A
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See Also: Transform protocols, IPsec protocols, Authentication
Header
7.11. NAT Traversal (NAT-T)
Definition: The capability to support IPsec functionality in the
presence of NAT devices.
Discussion: NAT-Traversal requires some modifications to IKE as
defined in [RFC3947]. Specifically, in phase 1, it requires
detecting if the other end supports NAT-Traversal, and detecting
if there are one or more NAT instances along the path from host to
host. In IKE Quick Mode, there is a need to negotiate the use of
UDP encapsulated IPsec packets.
NAT-T also describes how to transmit the original source and
destination addresses to the corresponding IPsec Device. The
original source and destination addresses are used in transport
mode to incrementally update the TCP/IP checksums so that they
will match after the NAT transform (The NAT cannot do this,
because the TCP/IP checksum is inside the UDP encapsulated IPsec
packet).
Issues: N/A
See Also: IKE, ISAKMP, IPsec Device
7.12. IP Compression
Definition: A mechanism as defined in [RFC2393] that reduces the
size of the payload that needs to be encrypted.
Discussion: IP payload compression is a protocol to reduce the size
of IP datagrams. This protocol will increase the overall
communication performance between a pair of communicating hosts/
gateways ("nodes") by compressing the datagrams, provided the
nodes have sufficient computation power, through either CPU
capacity or a compression coprocessor, and the communication is
over slow or congested links.
IP payload compression is especially useful when encryption is
applied to IP datagrams. Encrypting the IP datagram causes the
data to be random in nature, rendering compression at lower
protocol layers (e.g., PPP Compression Control Protocol [RFC1962])
ineffective. If both compression and encryption are required,
compression must be applied before encryption.
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Issues: N/A
See Also: IKE, ISAKMP, IPsec Device
7.13. Security Context
Definition: A security context is a collection of security
parameters that describe the characteristics of the path that an
IPsec Tunnel will take, all of the IPsec Tunnel parameters and the
effects it has on the underlying protected traffic. Security
Context encompasses protocol suite and security policy.
Discussion: In order to fairly compare multiple IPsec devices it is
imperative that an accurate overview is given of all security
parameters that were used to establish the IPsec Tunnels or
manually created SAs and to secure the traffic between protected
networks. Security Context is not a metric; it is included to
accurately reflect the test environment variables when reporting
the methodology results. To avoid listing too much information
when reporting metrics, we have divided the security context into
an IKE context and an IPsec context.
When merely discussing the behavior of traffic flows through IPsec
devices, an IPsec context MUST be provided. In other cases the
scope of a discussion or report may focus on a more broad set of
behavioral characteristics of the IPsec device, in which case both
an IPsec and an IKE context MUST be provided.
The IPsec context MUST consist of the following elements:
* Manual Keyed Tunnels versus IKE negotiated Tunnels
* Number of IPsec Tunnels or IPsec SA's
* IPsec protocol (AH or ESP)
* IPsec protocol mode (tunnel or transport)
* Authentication algorithm used by AH/ESP
* Encryption algoritm used ESP (if applicable)
* IPsec SA lifetime (traffic and time based)
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The IPsec Context MAY also list:
* Selectors
* Fragmentation handling
The IKE Context MUST consist of the following elements:
* Number of IPsec Tunnels.
+ IKE Phase 1 SA to IKE Phase 2 SA ratio (if applicable)
+ IKE Phase 1 parameters
- Authentication algorithm
- Encryption algorithm
- DH-Group
- SA lifetime (traffic and time based)
- Authentication mechanism (pre-shared key, RSA-sig,
certificate, etc)
+ IKE Phase 2 parameters
- IPsec protocol (part of IPsec context)
- IPsec protocol mode (part of IPsec context)
- Authentication algorithm (part of IPsec context)
- Encryption algorithm (part of IPsec context)
- DH-Group
- PFS used
- SA Lifetime (part of IPsec context)
* Keepalive or DPD values as defined in [I-D.ietf-ipsec-dpd]
* IP Compression [RFC2393]
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The IKE context MUST also list:
* Phase 1 mode (main or aggressive)
* Available bandwidth and latency to Certificate Authority server
(if applicable)
Issues: A Security Context will be an important element in
describing the environment where protected traffic is traveling
through.
See Also: IPsec Protocols, Transform Protocols, IKE Phase 1, IKE
phase 2, Selectors, IPsec Tunnel
8. Framesizes
8.1. Layer3 clear framesize
Definition: The total size of the unencrypted L3 PDU.
Discussion: In relation to IPsec this is the size of the IP header
and its payload. It SHALL NOT include any encapsulations that MAY
be applied before the PDU is processed for encryption.
IPv4 example: 46 bytes PDU = 20 bytes IP header + 26 bytes
payload.
The following table represents the min/max packet sizes for a
variety of IP packet types, including raw IPv6, IPv6 with typical
transport headers, and IPv6 with IPsec.
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MIN MAX
IPv6 40 1500*
IPv6+UDP 48
IPv6+TCP 60
ICMPv6 88
IPv6+AH+C 64 (transport mode compressed)
IPv6+ESP+C 74 (transport mode compressed
IPv6+T+AH+C 70 (tunnel mode compressed)
IPv6+T+ESP+C 80 (tunnel mode compressed)
Given robust header compression (ROHC), the minimum packet size is
derived as follows, e.g., for tunnel mode ESP:
IPv6 40 bytes
IPsec 34 (ESP, 192-bit ICV)
-+
IPv6 |- 6 byte ROHC of tunnel and transport headers
TCP |
-+
total -----------------
80 bytes
This 80 bytes assumes that the TCP payload is 0 bytes; it may be 1
byte (e.g., data sent reliably but with "NAGLE" off). Similar
ROHC sizes result from UDP sources.
Measurement Units: Bytes
Issues: N/A
See Also: Layer3 Encrypted Framesize, Layer2 Clear Framesize, Layer2
Encrypted Framesize.
8.2. Layer3 encrypted framesize
Definition: The total size of the encrypted L3 PDU.
Discussion: The size of the IP packet and its payload after
encapsulations MAY be applied and the PDU is being processed by
the transform.
For example, in IPv4, after a tunnel mode ESP 3DES/SHA1 transform
has been applied an unencrypted or clear layer3 framesize of 46
bytes Becomes 96 bytes:
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20 bytes outer IP header (tunnel mode)
4 bytes SPI (ESP header)
4 bytes Sequence (ESP Header)
8 bytes IV (IOS ESP-3DES)
46 bytes payload
0 bytes pad (ESP-3DES 64 bit)
1 byte Pad length (ESP Trailer)
1 byte Next Header (ESP Trailer)
12 bytes ESP-HMAC SHA1 96 digest
Measurement Units: Bytes
Issues: N/A
See Also: Layer3 Clear Framesize, Layer2 Clear Framesize, Layer2
Encrypted Framesize.
9. Performance Metrics
9.1. IPsec Tunnels Per Second (TPS)
Definition: The measurement unit for the IPsec Tunnel Setup Rate
tests. The rate at which IPsec Tunnels are established per
second.
Discussion: According to [RFC2401] two IPsec Tunnels cannot be
established between the same gateways with the same selectors.
This is to prevent overlapping IPsec Tunnels. If overlapping
IPsec Tunnels are attempted, the error will cause the IPsec Tunnel
setup time to take longer than if the IPsec Tunnel setup was
successful. For this reason, a unique pair of selector sets are
required for IPsec Tunnel Setup Rate testing.
Issues: A unique pair of selector sets are required for TPS testing.
See Also: IPsec Tunnel Setup Rate Behavior, IPsec Tunnel Setup Rate,
IKE Setup Rate, IPsec Setup Rate
9.2. Tunnel Rekeys Per Seconds (TRPS)
Definition: A metric that quantifies the number of IKE Phase 1 or
Phase 2 rekeys per seconds a DUT can correctly process.
Discussion: This metric will be will be primary used with Tunnel
Rekey behavior tests.
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TRPS will provide a metric used to see system behavior under
stressful conditions where large volumes of SA's are being rekeyed
at the same time or in a short timespan.
Issues: N/A
See Also: Tunnel Rekey Behavior, Phase 1 Rekey Rate, Phase 2 Rekey
Rate
9.3. IPsec Tunnel Attempts Per Second (TAPS)
Definition: A metric that quantifies the number of successful and
unsuccessful IPsec Tunnel establishment requests per second.
Discussion: This metric can be used to measure IKE DOS Resilience
behavior test.
TAPS provides an important metric to validate the stability of an
IPsec device, if stressed with valid (large number of IPsec tunnel
establishments per seconds or TPS) or invalid (IKE DOS attacks of
any style) tunnel establishment requests. IPsec Tunnel setups
offered to an IPsec devices can either fail due to lack of
resources in the IPsec device to process all the requests or due
to an IKE DOS attack (usually the former is a result of the
latter).
Issues: If the TAPS increases, the TPS usually decreases, due to
burdening of the DUT with the DOS attack traffic.
See Also: N/A
10. Test Definitions
10.1. Capacity
10.1.1. IKE SA Capacity
Definition: The maximum number of IKE SA's that can be sustained on
an IPsec Device.
Discussion: This metric will represent the quantity of peer a given
IPsec device can establish. It is the maximum number of Active
Tunnels that can be sustained by an IPsec Device.
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Measurement Units: IKE SA's
Issues: N/A
See Also: IPsec SA Capacity
10.1.2. IPsec SA Capacity
Definition: The maximum number of IPsec SA's that can be sustained
on an IPsec Device.
Discussion: This metric will represent the quantity of traffic flows
a given IPsec Device can protect. In contrast with the IKE SA
Capacity, the emphasis for this test lies on the number of IPsec
SA's that can be established in the worst case scenario. This
scenario would be a case where 1 IKE SA is used to negotiate
multiple IPsec SA's. It is the maximum number of Active Tunnels
that can be sustained by an IPsec Device where only 1 IKE SA is
used to exchange keying material.
Measurement Units: IPsec SA's
Issues: N/A
See Also: IKE SA Capacity
10.2. Throughput
10.2.1. IPsec Throughput
Definition: The maximum rate through an Active Tunnel at which none
of the offered frames are dropped by the device under test.
Discussion: The IPsec Throughput is almost identically defined as
Throughput in [RFC1242], section 3.17. The only difference is
that the throughput is measured with a traffic flow getting
encrypted and decrypted by an IPsec device. IPsec Throughput is
an end-to-end measurement.
The metric can be represented in two variantions depending on
where measurement is taken in the SUT. One can look at throughput
from a cleartext point of view i.e. find the maximum rate where
clearpackets no longer get dropped. This resulting rate can be
recalculated with an encrypted framesize to represent the
encryption throughput rate. The latter is the preferred method of
representation and shall be called the IPsec Throughput.
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Measurement Units: Packets per seconds (pps)
Issues: N/A
See Also: IPsec Encryption Throughput, IPsec Decryption Throughput
10.2.2. IPsec Encryption Throughput
Definition: The maximum encryption rate through an Active Tunnel at
which none of the offered cleartext frames are dropped by the
device under test.
Discussion: Since encryption throughput is not necessarily equal to
the decryption throughput, both of the forwarding rates must be
measured independently. The independent forwarding rates have to
measured with the help of an IPsec aware test device that can
originate and terminate IPsec and IKE SA. As defined in
[RFC1242], measurements should be taken with an assortment of
frame sizes.
Measurement Units: Packets per seconds (pps)
Issues: In some cases packets are offered to an IPsec Device that
have a framesize that is larger then the MTU of the ingress
interface of the IPsec Tunnel that is transporting the packet. In
this case fragmentation will be required before IPsec services are
applied.
In other cases, the packet is of a size very close to the MTU of
the egress interface of the IPsec Tunnel. Here, the mere addition
of the IPsec header will create enough overhead to make the IPsec
packet larger then the MTU of the egress interface. In such
instance, the original payload packet must be fragmented either
before or after the IPsec overhead is applied.
Note that the two aforementioned scenario's can happen
simultaniously on a single packet, creating multiple small
fragments.
When measuring the IPsec Encryption Throughput, one has to
consider that when probing with packets of a size near MTU's
associated with the IPsec Tunnel, fragmentation may accor and the
decrypting IPsec Device (either a tester or a corresponding IPsec
peer) has to reassemble the IPsec and/or payload fragments to
validate its content.
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The end points (i.e. hosts, subnets) should NOT see any fragments
at ANY time. Only on the IPsec link, fragments MAY occur.
See Also: IPsec Throughput, IPsec Decryption Throughput
10.2.3. IPsec Decryption Throughput
Definition: The maximum decryption rate through an Active Tunnel at
which none of the offered encrypted frames are dropped by the
device under test.
Discussion: Since encryption throughput is not necessarily equal to
the decryption throughput, both of the forwarding rates must be
measured independently.
The independent forwarding rates have to be measured with the help
of an IPsec aware test device that can originate and terminate
IPsec and IKE SA. As defined in [RFC1242], measurements should be
taken with an assortment of frame sizes.
Measurement Units: Packets per seconds (pps)
Issues: When measuring the IPsec Decryption Throughput, one has to
consider that it is likely that the encrypting IPsec Device has to
fragment certain packets that have a frame size near MTU's
associated with the IPsec Tunnel.
The decrypting IPsec Device has to reassemble the IPsec and/or
payload fragments to validate its content.
The end points (i.e. hosts, subnets) should NOT see any fragments
at ANY time. Only on the IPsec link, fragments MAY occur.
See Also: IPsec Throughput, IPsec Encryption Throughput
10.3. Latency
10.3.1. IPsec Latency
Definition: Time required to propagate a cleartext frame from the
input interface of an initiator, through an Active Tunnel, to the
output interface of the responder.
Discussion: The IPsec Latency is the time interval starting when the
end of the first bit of the cleartext frame reaches the input
interface of the initiator and ending when the start of the first
bit of the same cleartext frame is detected on the output
interface of the responder. The frame has passed through an
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Active Tunnel between an initiator and a responder and has been
through an encryption and decryption cycle.
Measurement Units: Time units with enough precision to reflect
latency measurement.
Issues: N/A
See Also: IPsec Encryption Latency, IPsec Decryption Latency
10.3.2. IPsec Encryption Latency
Definition: The IPsec Encryption Latency is the time interval
starting when the end of the first bit of the cleartext frame
reaches the input interface, through an Active Tunnel, and ending
when the start of the first bit of the encrypted output frame is
seen on the output interface.
Discussion: IPsec Encryption Latency is the latency introduced when
encrypting traffic through an IPsec tunnel.
Like encryption/decryption throughput, it is not always the case
that encryption latency equals the decryption latency. Therefore
a distinction between the two has to be made in order to get a
more accurate view of where the latency is the most pronounced.
The independent encryption/decryption latencies have to be
measured with the help of an IPsec aware test device that can
originate and terminate IPsec and IKE SA. As defined in
[RFC1242], measurements should be taken with an assortment of
frame sizes.
Measurement Units: Time units with enough precision to reflect
latency measurement.
Issues: N/A
See Also: IPsec Latency, IPsec Decryption Latency
10.3.3. IPsec Decryption Latency
Definition: The IPsec decryption Latency is the time interval
starting when the end of the first bit of the encrypted frame
reaches the input interface, through an Active Tunnel, and ending
when the start of the first bit of the decrypted output frame is
seen on the output interface.
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Discussion: IPsec Decryption Latency is the latency introduced when
decrypting traffic through an Active Tunnel. Like encryption/
decryption throughput, it is not always the case that encryption
latency equals the decryption latency. Therefore a distinction
between the two has to be made in order to get a more accurate
view of where the latency is the most pronounced.
The independent encryption/decryption latencies have to be
measured with the help of an IPsec aware test device that can
originate and terminate IPsec and IKE SA's. As defined in
[RFC1242], measurements should be taken with an assortment of
frame sizes.
Measurement Units: Time units with enough precision to reflect
latency measurement.
Issues: N/A
See Also: IPsec Latency, IPsec Encryption Latency
10.3.4. Time To First Packet
Definition: The Time To First Packet (TTFP) is the time required to
process a cleartext packet from a traffic stream that requires
encryption services when no IPsec Tunnel is present.
Discussion: The Time To First Packet addresses the issue of
responsiveness of an IPsec device by looking how long it takes to
transmit a packet over Configured Tunnel. The Time To First
Packet MUST include the time to set up the established tunnel,
triggered by the traffic flow (both phase 1 and phase 2 setup
times SHALL be included) and the time it takes to encrypt and
decrypt the packet on a corresponding peer. In short it is the
IPsec Tunnel setup time plus the propagation delay of the packet
through the Active Tunnel.
It must be noted that it is highly unlikely that the first packet
of the traffic flow will be the packet that will be used to
measure the TTFP. There MAY be several protocol layers in the
stack before the tunnel is formed and the traffic is forwarded,
hence several packets COULD be lost during negotiation, for
example, ARP and/or IKE.
Measurement Units: Time units with enough precision to reflect a
TTFP measurement.
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Issues: Only relevant when using IKE for tunnel negotiation.
10.4. Frame Loss
10.4.1. IPsec Frame Loss
Definition: Percentage of cleartext frames that should have been
forwarded through an Active Tunnel under steady state (constant)
load but were dropped before encryption or after decryption.
Discussion: The IPsec Frame Loss is almost identically defined as
Frame Loss Rate in [RFC1242], section 3.6. The only difference is
that the IPsec Frame Loss is measured with a traffic flow getting
encrypted and decrypted by an IPsec Device. IPsec Frame Loss is
an end-to-end measurement.
Measurement Units: Percent (%)
Issues: N/A
See Also: IPsec Encryption Frame Loss, IPsec Decryption Frame Loss
10.4.2. IPsec Encryption Frame Loss
Definition: Percentage of cleartext frames that should have been
encrypted through an Active Tunnel under steady state (constant)
load but were dropped.
Discussion: A DUT will always have an inherent forwarding
limitation. This will be more pronounced when IPsec is employed
on the DUT. There is a possibility that the offered traffic rate
at the Active Tunnel is too high to be transported through the
Active Tunnel and not all cleartext packets will get encrypted.
In that case, some percentage of the cleartext traffic will be
dropped. This drop percentage is called the IPsec Encryption
Frame Loss.
Measurement Units: Percent (%)
Issues: N/A
See Also: IPsec Frame Loss, IPsec Decryption Frame Loss
10.4.3. IPsec Decryption Frame Loss
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Definition: Percentage of encrypted frames that should have been
decrypted through an Active Tunnel under steady state (constant)
load but were dropped.
Discussion: A DUT will also have an inherent forwarding limitation
when decrypting packets. When Active Tunnel encrypted traffic is
offered at a costant load, there might be a possibility that the
IPsec Device that needs to decrypt the traffic will not be able to
perfom this action on all of the packets due to limitations of the
decryption performance. The percentage of encrypted frames that
would get dropped under these conditions is called the IPsec
Decryption Frame Loss.
Measurement Units: Percent (%)
Issues: N/A
See Also: IPsec Frame Loss, IPsec Encryption Frame Loss
10.4.4. IKE Phase 2 Rekey Frame Loss
Definition: Number of frames dropped as a result of an inefficient
IKE Phase 2 rekey.
Discussion: Normal operation of an IPsec Device would require that a
rekey does not create temporary IPsec Frame Loss of a traffic
stream that is protected by the IKE Phase 2 SA's (i.e. IPsec
SA's). Nevertheless there can be situations where IPsec Frame
Loss occurs during this rekey process.
This metric should be ideally zero but this may not be the case on
IPsec Devices where IPsec funtionality is not a core feature.
Measurement Units: Number of N-octet frames
Issues: N/A
See Also: IKE Phase 2 Rekey Rate
10.5. Back-to-back Frames
10.5.1. IPsec Back-to-back Frames
Definition: A burst of cleartext frames, offered at a constant load
that can be sent through an Active Tunnel without losing a single
cleartext frame after decryption.
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Discussion: The IPsec Back-to-back Frames is almost identically
defined as Back-to-back in [RFC1242], section 3.1. The only
difference is that the IPsec Back-to-back Frames is measured with
a traffic flow getting encrypted and decrypted by an IPsec Device.
IPsec Back-to-back Frames is an end-to-end measurement.
Measurement Units: Number of N-octet frames in burst.
Issues: Recommended test frame sizes will be addressed in
methodology document.
See Also: IPsec Encryption Back-to-back frames, IPsec Decryption
Back-to-back frames
10.5.2. IPsec Encryption Back-to-back Frames
Definition: A burst of cleartext frames, offered at a constant load
that can be sent through an Active Tunnel without losing a single
encrypted frame.
Discussion: IPsec Encryption back-to-back frames is the measure of
the maximum burst size that an IPsec Device can handle for
encrypting traffic that it receives as plaintext. Since it is not
necessarily the case that the maximum burst size a DUT can handle
for encryption is equal to the maximum burst size a DUT can handle
for decryption, both of these capabilities must be measured
independently. The IPsec Encryption Back-to-back frame
measurement has to be measured with the help of an IPsec aware
test device that can decrypt the traffic to determine the validity
of the encrypted frames.
Measurement Units: Number of N-octet frames in burst.
Issues: Recommended test frame sizes will be addressed in future
methodology document.
See Also: IPsec Back-to-back frames, IPsec Decryption Back-to-back
frames
10.5.3. IPsec Decryption Back-to-back Frames
Definition: The number of encrypted frames, offered at a constant
load, that can be sent through an Active Tunnel without losing a
single cleartext frame.
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Discussion: IPsec Decryption Back-to-back frames is the measure of
the maximum burst size that an IPsec Device can handle for
decrypting traffic that it receives as encrypted traffic. Since
it is not necessarily the case that the maximum burst size a DUT
can handle for decryption is equal to the maximum burst size a DUT
can handle for encryption, both of these capabilities must be
measured independently. The IPsec Decryption Back-to-back frame
measurement has to be measured with the help of an IPsec aware
testdevice that can determine the validity of the decrypted
frames.
Measurement Units: Number of N-octet frames in burst.
Issues: Recommended test frame sizes will be addressed in
methodology document.
See Also: IPsec Back-to-back frames, IPsec Encryption back-to-back
frames
10.6. Tunnel Setup Behavior
10.6.1. IPsec Tunnel Setup Rate
Definition: The maximum number of IPsec Tunnels per second that an
IPsec Device can successfully establish.
Discussion: The Tunnel Setup Rate SHOULD be measured at varying
number of IPsec Tunnels (1 Phase 1 SA and 2 Phase 2 SA's) on the
DUT. Several factors may influence Tunnel Setup Rate, such as:
TAPS rate, Background cleartext traffic load on the secure
interface, Already established IPsec Tunnels, Authentication
method such as pre-shared keys, RSA-encryption, RSA-signature, DSS
Key sizes used (when using RSA/DSS).
Measurement Units: Tunnels Per Second (TPS)
Issues: N/A
See Also: IKE Phase 1 Setup Rate, IKE Phase 2 Setup Rate, IPsec
Tunnel Rekey Behavior
10.6.2. IKE Phase 1 Setup Rate
Definition: The maximum number of sucessful IKE Phase 1 SA's per
second that an IPsec Device can establish.
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Discussion: The Phase 1 Setup Rate is a portion of the IPsec Tunnel
Setup Rate. In the process of establishing an IPsec Tunnel, it is
interesting to know what the limiting factor of the IKE Finite
State Machine (FSM) is i.e. is it limited by the Phase 1
processing delays or rather by the Phase 2 processing delays.
Measurement Units: Tunnels Per Second (TPS)
Issues: N/A
See Also: IPsec Tunnel Setup Rate, IKE Phase 2 Setup Rate, IPsec
Tunnel Rekey Behavior
10.6.3. IKE Phase 2 Setup Rate
Definition: The maximum number of successfully IKE Phase 2 SA's per
second that an IPsec Device can Only relevant when using IKE
establish.
Discussion: The IKE Phase 2 Setup Rate is a portion of the IPsec
Tunnel Setup Rate. For identical reasons why it is required to
quantify the IKE Phase 1 Setup Rate, it is a good practice to know
the processing delays involved in setting up an IKE Phase 2 SA for
each direction of the protected traffic flow.
IKE Phase 2 Setup Rates will ALWAYS be measured for multiples of
two IKE Phase 2 SA's.
Note that once you have the IPsec Tunnel Setup Rate and either the
IKE Phase 1 or the IKE Phase 2 Setup Rate data, you can
extrapolate the unmeasured metric. It is however highly
RECOMMENDED to measure all three metrics.
Measurement Units: Tunnels Per Second (TPS)
Issues: N/A
See Also: IPsec Tunnel Setup Rate, IKE Phase 1 Setup Rate, IPsec
Tunnel Rekey Behavior
10.7. IPsec Tunnel Rekey Behavior
10.7.1. IKE Phase 1 Rekey Rate
Definition: The number of IKE Phase 1 SA's that can be succesfully
re-establish per second.
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Discussion: Although the IKE Phase 1 Rekey Rate has less impact on
the forwarding behavior of traffic that requires security services
then the IKE Phase 2 Rekey Rate, it can pose a large burden on the
CPU or network processor of the IPsec Device. Due to the highly
computational nature of a Phase 1 exchange, it may impact the
stability of Active Tunnels in the network when the IPsec Device
fails to properly rekey an IKE Phase 1 SA.
Measurement Units: Tunnel Rekeys per second (TRPS)
Issues: N/A
See Also: IKE Phase 2 Rekey Rate
10.7.2. IKE Phase 2 Rekey Rate
Definition: The number of IKE Phase 2 SA's that can be succesfully
re-negotiated per second.
Discussion: Although many implementations will usually derive new
keying material before the old keys expire, there may still be a
period of time where frames get dropped before the IKE Phase 2
tunnels are successfully re-established. There may also be some
packet loss introduced when the handover of traffic is done from
the expired IPsec SA's to the newly negotiated IPsec SA's. To
measure the IKE Phase 2 rekey rate, the measurement will require
an IPsec aware test device to act as a responder when negotiating
the new IKE Phase 2 keying material.
The test methodology report must specify if PFS is enabled in
reported security context.
Measurement Units: Tunnel Rekeys per second (TRPS)
Issues: N/A
See Also: IKE Phase 1 Rekey Rate
10.8. IPsec Tunnel Failover Time
Definition: Time required to recover all IPsec Tunnels on a stanby
IPsec Device, after a catastrophic failure occurs on the active
IPsec Device.
Discussion: Recovery time required to re-establish all IPsec Tunnels
and reroute all traffic on a standby node or other failsafe system
after a failure has occurred in the DUT/SUT. Failure can include
but are not limited to a catastrophic IPsec Device failure, a
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encryption engine failure, link outage, etc ... . The recovery
time is delta between the point of failure and the time the first
packet is seen on the last restored IPsec Tunnel on the backup
device.
Measurement Units: Time units with enough precision to reflect IPsec
Tunnel Failover Time.
Issues: N/A
10.9. DoS Attack Resiliency
10.9.1. Phase 1 DoS Resiliency Rate
Definition: The Phase 1 Denial of Service (DoS) Resilience Rate
quantifies the rate of invalid or malicious IKE tunnels that can
be directed at a DUT before the Responder stops accepting valid
tunnel attempts.
Discussion: Phase 1 DoS attacks can present themselves in various
forms and do not necessarily have to have a malicious background.
It is sufficient to make a typographical error in a shared secret
in an IPsec Device to be susceptible to a large number of IKE
attempts that need to be turned down. Due to the intense
computational nature of an IKE exchange every single IKE tunnel
attempt that has to be denied will take non-negligible CPU cycles
in the IPsec Device.
Depending on the quantity of these messages that have to be
processed, a system might end up in a state that the burden on the
CPU of doing key exchanges is high enough that the entire CPU is
consumed by this process. At this point it will be no longer
possible to process a valid IKE tunnel setup request and thus a
Phase 1 DoS Attack is in effect.
The scope of the attack profile for this test will include
mismatched pre-shared keys as well as invalid digital
certificates.
Measurement Units: Tunnel Attempts Per Seconds (TAPS)
Issues: N/A
10.9.2. Phase 2 DoS Resiliency Rate
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Definition: The Phase 2 Denial of Service (DoS) Resilience Rate
quantifies the rate of invalid ESP/AH packets that a DUT can drop
without affecting the traffic flow of valid ESP/AH packets.
Discussion: Phase 2 DoS attacks can present themselves in various
forms and do not necessarily have to have a malicious background,
but usually are. A well know case where there is no malicious
intent is when packets are dropped due to anti-replay errors,
which can be caused by applying a queueing mechanism after
encryption. More typical are cases where there is a true
malicious intent in the ESP/AH traffic flow by e.g. having an
invalid hash in the IPsec data packets.
Depending on the quantity of these packets that have to be
processed, a system might end up in a state that the burden on the
IPsec Device becomes large enough that it will impact valid
traffic flows. At this point it will be no longer possible to
forward valid IPsec payload without packetloss and thus a Phase 2
DoS Attack is in effect.
Measurement Units: Packets per seconds (pps)
Issues: N/A
11. Security Considerations
As this document is solely for the purpose of providing test
benchmarking terminology and describes neither a protocol nor a
protocol's implementation; there are no security considerations
associated with this document.
12. Acknowledgements
The authors would like to acknowledge the following individual for
their participation of the compilation and editing of this document
and guidance: Debby Stopp, Paul Hoffman, Sunil Kalidindi, Brian
Talbert.
13. References
13.1. Normative References
[RFC1242] Bradner, S., "Benchmarking terminology for network
interconnection devices", RFC 1242, July 1991.
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[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2285] Mandeville, R., "Benchmarking Terminology for LAN
Switching Devices", RFC 2285, February 1998.
[RFC2393] Shacham, A., Monsour, R., Pereira, R., and M. Thomas, "IP
Payload Compression Protocol (IPComp)", RFC 2393,
December 1998.
[RFC2401] Kent, S. and R. Atkinson, "Security Architecture for the
Internet Protocol", RFC 2401, November 1998.
[RFC2402] Kent, S. and R. Atkinson, "IP Authentication Header",
RFC 2402, November 1998.
[RFC2403] Madson, C. and R. Glenn, "The Use of HMAC-MD5-96 within
ESP and AH", RFC 2403, November 1998.
[RFC2404] Madson, C. and R. Glenn, "The Use of HMAC-SHA-1-96 within
ESP and AH", RFC 2404, November 1998.
[RFC2405] Madson, C. and N. Doraswamy, "The ESP DES-CBC Cipher
Algorithm With Explicit IV", RFC 2405, November 1998.
[RFC2406] Kent, S. and R. Atkinson, "IP Encapsulating Security
Payload (ESP)", RFC 2406, November 1998.
[RFC2407] Piper, D., "The Internet IP Security Domain of
Interpretation for ISAKMP", RFC 2407, November 1998.
[RFC2408] Maughan, D., Schneider, M., and M. Schertler, "Internet
Security Association and Key Management Protocol
(ISAKMP)", RFC 2408, November 1998.
[RFC2409] Harkins, D. and D. Carrel, "The Internet Key Exchange
(IKE)", RFC 2409, November 1998.
[RFC2410] Glenn, R. and S. Kent, "The NULL Encryption Algorithm and
Its Use With IPsec", RFC 2410, November 1998.
[RFC2411] Thayer, R., Doraswamy, N., and R. Glenn, "IP Security
Document Roadmap", RFC 2411, November 1998.
[RFC2412] Orman, H., "The OAKLEY Key Determination Protocol",
RFC 2412, November 1998.
[RFC2451] Pereira, R. and R. Adams, "The ESP CBC-Mode Cipher
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Algorithms", RFC 2451, November 1998.
[RFC2544] Bradner, S. and J. McQuaid, "Benchmarking Methodology for
Network Interconnect Devices", RFC 2544, March 1999.
[RFC2547] Rosen, E. and Y. Rekhter, "BGP/MPLS VPNs", RFC 2547,
March 1999.
[RFC2661] Townsley, W., Valencia, A., Rubens, A., Pall, G., Zorn,
G., and B. Palter, "Layer Two Tunneling Protocol "L2TP"",
RFC 2661, August 1999.
[RFC2784] Farinacci, D., Li, T., Hanks, S., Meyer, D., and P.
Traina, "Generic Routing Encapsulation (GRE)", RFC 2784,
March 2000.
[RFC3947] Kivinen, T., Swander, B., Huttunen, A., and V. Volpe,
"Negotiation of NAT-Traversal in the IKE", RFC 3947,
January 2005.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, December 2005.
[RFC4302] Kent, S., "IP Authentication Header", RFC 4302,
December 2005.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, December 2005.
[RFC4306] Kaufman, C., "Internet Key Exchange (IKEv2) Protocol",
RFC 4306, December 2005.
[I-D.ietf-ipsec-ikev2]
Kaufman, C., "Internet Key Exchange (IKEv2) Protocol",
draft-ietf-ipsec-ikev2-17 (work in progress),
October 2004.
[I-D.ietf-ipsec-dpd]
Huang, G., Beaulieu, S., and D. Rochefort, "A Traffic-
Based Method of Detecting Dead IKE Peers",
draft-ietf-ipsec-dpd-04 (work in progress), October 2003.
[I-D.ietf-ipsec-properties]
Krywaniuk, A., "Security Properties of the IPsec Protocol
Suite", draft-ietf-ipsec-properties-02 (work in progress),
July 2002.
[FIPS.186-1.1998]
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National Institute of Standards and Technology, "Digital
Signature Standard", FIPS PUB 186-1, December 1998,
<http://csrc.nist.gov/fips/fips1861.pdf>.
13.2. Informative References
[Designing Network Security]
Kaeo, M., "Designing Network Security", ISBN: 1578700434,
Published: May 07, 1999; Copyright: 1999, 1999.
[SKEME] Krawczyk, H., "SKEME: A Versatile Secure Key Exchange
Mechanism for Internet", from IEEE Proceedings of the
1996 Symposium on Network and Distributed Systems
Security,
URI http://www.research.ibm.com/security/skeme.ps, 1996.
Authors' Addresses
Merike Kaeo
Double Shot Security
3518 Fremont Ave N #363
Seattle, WA 98103
USA
Phone: +1(310)866-0165
Email: kaeo@merike.com
Tim Van Herck
Cisco Systems
170 West Tasman Drive
San Jose, CA 95134-1706
USA
Phone: +1(408)853-2284
Email: herckt@cisco.com
Michele Bustos
IXIA
26601 W. Agoura Rd.
Calabasas, CA 91302
USA
Phone: +1(818)444-3244
Email: mbustos@ixiacom.com
Kaeo, et al. Expires January 9, 2008 [Page 47]
Internet-Draft Benchmarking IPsec - Terminology July 2007
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