draft-ietf-sidr-bgpsec-ops-09.txt   draft-ietf-sidr-bgpsec-ops-10.txt 
Network Working Group R. Bush Network Working Group R. Bush
Internet-Draft Internet Initiative Japan Internet-Draft Internet Initiative Japan
Intended status: Best Current Practice June 16, 2016 Intended status: Best Current Practice June 23, 2016
Expires: December 18, 2016 Expires: December 25, 2016
BGPsec Operational Considerations BGPsec Operational Considerations
draft-ietf-sidr-bgpsec-ops-09 draft-ietf-sidr-bgpsec-ops-10
Abstract Abstract
Deployment of the BGPsec architecture and protocols has many Deployment of the BGPsec architecture and protocols has many
operational considerations. This document attempts to collect and operational considerations. This document attempts to collect and
present the most critical and universal. It is expected to evolve as present the most critical and universal. It is expected to evolve as
BGPsec is formalized and initially deployed. BGPsec is formalized and initially deployed.
Requirements Language Requirements Language
skipping to change at page 1, line 41 skipping to change at page 1, line 41
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on December 18, 2016. This Internet-Draft will expire on December 25, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 20 skipping to change at page 2, line 20
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Suggested Reading . . . . . . . . . . . . . . . . . . . . . . 3 2. Suggested Reading . . . . . . . . . . . . . . . . . . . . . . 3
3. RPKI Distribution and Maintenance . . . . . . . . . . . . . . 3 3. RPKI Distribution and Maintenance . . . . . . . . . . . . . . 3
4. AS/Router Certificates . . . . . . . . . . . . . . . . . . . 3 4. AS/Router Certificates . . . . . . . . . . . . . . . . . . . 3
5. Within a Network . . . . . . . . . . . . . . . . . . . . . . 3 5. Within a Network . . . . . . . . . . . . . . . . . . . . . . 3
6. Considerations for Edge Sites . . . . . . . . . . . . . . . . 4 6. Considerations for Edge Sites . . . . . . . . . . . . . . . . 4
7. Routing Policy . . . . . . . . . . . . . . . . . . . . . . . 5 7. Routing Policy . . . . . . . . . . . . . . . . . . . . . . . 4
8. Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 8. Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
9. Security Considerations . . . . . . . . . . . . . . . . . . . 7 9. Security Considerations . . . . . . . . . . . . . . . . . . . 7
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 7 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 7
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 7 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
12.1. Normative References . . . . . . . . . . . . . . . . . . 7 12.1. Normative References . . . . . . . . . . . . . . . . . . 7
12.2. Informative References . . . . . . . . . . . . . . . . . 8 12.2. Informative References . . . . . . . . . . . . . . . . . 8
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 9 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction 1. Introduction
BGPsec, [I-D.ietf-sidr-bgpsec-overview], is a new protocol with many BGPsec, [I-D.ietf-sidr-bgpsec-overview], is a new protocol with many
operational considerations. It is expected to be deployed operational considerations. It is expected to be deployed
incrementally over a number of years. As core BGPsec-capable routers incrementally over a number of years. As core BGPsec-capable routers
may require large memory and/or modern CPUs, it is thought that may require large memory and/or modern CPUs, it is thought that
origin validation based on the RPKI, [RFC6811], will occur over the origin validation based on the RPKI, [RFC6811], will occur over the
next two to three years and that BGPsec will start to deploy well next two to three years and that BGPsec will start to deploy well
after that. after that.
BGPsec relies on widespread propagation of the Resource Public Key BGPsec relies on widespread propagation of the Resource Public Key
Infrastructure (RPKI) [RFC6480]. How the RPKI is distributed and Infrastructure (RPKI) [RFC6480]. How the RPKI is distributed and
maintained globally and within an operator's infrastructure may be maintained globally and within an operator's infrastructure may be
different for BGPsec than for origin validation. different for BGPsec than for origin validation.
BGPsec need be spoken only by an AS's eBGP speaking, AKA border, BGPsec needs to be spoken only by an AS's eBGP speaking, AKA border,
routers, and is designed so that it can be used to protect routers, and is designed so that it can be used to protect
announcements which are originated by small edge routers. This has announcements which are originated by resource constrained edge
special operational considerations. routers. This has special operational considerations.
Different prefixes may have different timing and replay protection Different prefixes may have different timing and replay protection
considerations. considerations.
2. Suggested Reading 2. Suggested Reading
It is assumed that the reader understands BGP, [RFC4271], BGPsec, It is assumed that the reader understands BGP, see [RFC4271], BGPsec,
[I-D.ietf-sidr-bgpsec-overview], the RPKI, see [RFC6480], the RPKI [I-D.ietf-sidr-bgpsec-overview], the RPKI, see [RFC6480], the RPKI
Repository Structure, see [RFC6481], and ROAs, see [RFC6482]. Repository Structure, see [RFC6481], and ROAs, see [RFC6482].
3. RPKI Distribution and Maintenance 3. RPKI Distribution and Maintenance
All non-ROA considerations in the section on RPKI Distribution and All non-ROA considerations in the section on RPKI Distribution and
Maintenance of [RFC7115] apply. Maintenance of [RFC7115] apply.
4. AS/Router Certificates 4. AS/Router Certificates
skipping to change at page 3, line 47 skipping to change at page 3, line 47
propagation delay for provisioning the new key. propagation delay for provisioning the new key.
5. Within a Network 5. Within a Network
BGPsec is spoken by edge routers in a network, those which border BGPsec is spoken by edge routers in a network, those which border
other networks/ASs. other networks/ASs.
In a fully BGPsec enabled AS, Route Reflectors MUST have BGPsec In a fully BGPsec enabled AS, Route Reflectors MUST have BGPsec
enabled if and only if there are eBGP speakers in their client cone, enabled if and only if there are eBGP speakers in their client cone,
i.e. an RR client or the transitive closure of their customers' i.e. an RR client or the transitive closure of their customers'
customers' customers' .... customers' customers' etc.
A BGPsec capable router MAY use the data it receives to influence A BGPsec capable router MAY use the data it receives to influence
local policy within its network, see Section 7. In deployment this local policy within its network, see Section 7. In deployment this
policy should fit into the AS's existing policy, preferences, etc. policy should fit into the AS's existing policy, preferences, etc.
This allows a network to incrementally deploy BGPsec enabled border This allows a network to incrementally deploy BGPsec enabled border
routers. routers.
eBGP speakers which face more critical peers or up/downstreams would eBGP speakers which face more critical peers or up/downstreams would
be candidates for early deployment. Both securing one's own be candidates for early deployment. Both securing one's own
skipping to change at page 4, line 32 skipping to change at page 4, line 32
As they are not formally verifiable, an eBGP listener SHOULD NOT As they are not formally verifiable, an eBGP listener SHOULD NOT
strongly trust unsigned security markings such as communities strongly trust unsigned security markings such as communities
received across a trust boundary. received across a trust boundary.
6. Considerations for Edge Sites 6. Considerations for Edge Sites
An edge site which does not provide transit and trusts its An edge site which does not provide transit and trusts its
upstream(s) SHOULD only originate a signed prefix announcement and upstream(s) SHOULD only originate a signed prefix announcement and
need not validate received announcements. need not validate received announcements.
BGPsec protocol capability negotiation provides for a speaker signing
the data it sends without being able to accept signed data. Thus a
smallish edge router may hold only its own signing key(s), sign its
announcements, but not receive signed announcements and therefore not
need to deal with the majority of the RPKI. Thus such routers CPU,
RAM, and crypto needs are trivial and additional hardware should not
be needed.
Operators might need to use hardware with limited resources. In such Operators might need to use hardware with limited resources. In such
cases, BGPsec protocol capability negotiation allows for a resource cases, BGPsec protocol capability negotiation allows for a resource
constrained edge router to hold only its own signing key(s) and sign constrained edge router to hold only its own signing key(s) and sign
its announcements, but not receive signed announcements. Therefore, its announcements, but not receive signed announcements. Therefore,
the router would not have to deal with the majority of the RPKI, the router would not have to deal with the majority of the RPKI,
potentially saving the need for additional hardware. potentially saving the need for additional hardware.
As the vast majority (84%) of ASs are stubs, and they announce the As the vast majority (84%) of ASs are stubs, and they announce the
majority of prefixes, this allows for simpler and less expensive majority of prefixes, this allows for simpler and less expensive
incremental deployment. It may also mean that edge sites concerned incremental deployment. It may also mean that edge sites concerned
with routing security will be attracted to upstreams which support with routing security will be attracted to upstreams which support
BGPsec. BGPsec.
7. Routing Policy 7. Routing Policy
Unlike origin validation based on the RPKI, BGPsec marks a received Unlike origin validation based on the RPKI, BGPsec marks a received
announcement as Valid or Invalid, there is no explicit NotFound announcement as Valid or Not Valid, there is no explicit NotFound
state. In some sense, an unsigned BGP4 path is the equivalent of state. In some sense, an unsigned BGP4 path is the equivalent of
NotFound. How this is used in routing is up to the operator's local NotFound. How this is used in routing is up to the operator's local
policy. See [RFC6811]. policy, similar to origin validation as in [RFC6811].
As BGPsec will be rolled out over years and does not allow for As BGPsec will be rolled out over years and does not allow for
intermediate non-signing edge routers, coverage will be spotty for a intermediate non-signing edge routers, coverage will be spotty for a
long time. Hence a normal operator's policy SHOULD NOT be overly long time. Hence a normal operator's policy SHOULD NOT be overly
strict, perhaps preferring Valid paths and giving very low strict, perhaps preferring Valid paths and giving very low
preference, but still using, Invalid paths. preference, but still using, Not Valid paths.
Operators should be aware that accepting Invalid announcements, no Operators should be aware that accepting Not Valid announcements, no
matter how de-preffed, will often be the equivalent of treating them matter the local preference, will often be the equivalent of treating
as fully Valid. Consider having a Valid announcement from neighbor V them as fully Valid. Local preference affects only routes to the
for prefix 10.0.0.0/16 and an Invalid announcement for 10.0.666.0/24 same set of destinations. Consider having a Valid announcement from
from neighbor I. If local policy on the router is not configured to neighbor V for prefix 10.0.0.0/16 and an Not Valid announcement for
discard the Invalid announcement from I, then longest match 10.0.666.0/24 from neighbor I. If local policy on the router is not
forwarding will send packets to neighbor I no matter the value of configured to discard the Not Valid announcement from I, then longest
local preference. match forwarding will send packets to neighbor I no matter the value
of local preference.
A BGPsec speaker validates signed paths at the eBGP edge. Validation of signed paths is usually deployed at the eBGP edge.
Local policy on the eBGP edge MAY convey the validation state of a Local policy on the eBGP edge MAY convey the validation state of a
BGP signed path through normal local policy mechanisms, e.g. setting BGP signed path through normal local policy mechanisms, e.g. setting
a BGP community for internal use, or modifying a metric value such as a BGP community for internal use, or modifying a metric value such as
local-preference or MED. Some may choose to use the large Local-Pref local-preference or MED. Some may choose to use the large Local-Pref
hammer. Others may choose to let AS-Path rule and set their internal hammer. Others may choose to let AS-Path rule and set their internal
metric, which comes after AS-Path in the BGP decision process. metric, which comes after AS-Path in the BGP decision process.
Because of possible RPKI version skew, an AS Path which does not Because of possible RPKI version skew, an AS Path which does not
validate at router R0 might validate at R1. Therefore, signed paths validate at router R0 might validate at R1. Therefore, signed paths
that are Invalid and yet propagated (because they are chosen as best that are Not Valid and yet propagated (because they are chosen as
path) SHOULD have their signatures kept intact and MUST be signed if best path) SHOULD have their signatures kept intact and MUST be
sent to external BGPsec speakers. signed if sent to external BGPsec speakers.
This implies that updates which a speaker judges to be Invalid MAY be This implies that updates which a speaker judges to be Not Valid MAY
propagated to iBGP peers. Therefore, unless local policy ensures be propagated to iBGP peers. Therefore, unless local policy ensures
otherwise, a signed path learned via iBGP MAY be Invalid. If needed, otherwise, a signed path learned via iBGP MAY be Not Valid. If
the validation state should be signaled by normal local policy needed, the validation state should be signaled by normal local
mechanisms such as communities or metrics. policy mechanisms such as communities or metrics.
On the other hand, local policy on the eBGP edge might preclude iBGP On the other hand, local policy on the eBGP edge might preclude iBGP
or eBGP announcement of signed AS Paths which are Invalid. or eBGP announcement of signed AS Paths which are Not Valid.
A BGPsec speaker receiving a path SHOULD perform origin validation A BGPsec speaker receiving a path SHOULD perform origin validation
per [RFC6811] and [RFC7115]. per [RFC6811] and [RFC7115].
A route server is usually 'transparent', most importantly not A route server is usually 'transparent'. To operate transparently in
inserting its own AS into the AS_Path, to not lengthen the AS hop an environment in which the route server connects BGPsec-enabled
count and thereby reduce the likelihood of best path selection. See peers, the route server MUST run BGPsec as well. A BGPsec-aware
2.2.2 of [I-D.ietf-idr-ix-bgp-route-server]. A BGPsec-aware route route server needs to validate the incoming BGPsec_Path, and to
server needs to validate the incoming BGPSEC_Path, and to forward forward updates which can be validated by clients which know the
updates which can be validated by clients which know the route route server's AS. This implies that the route server creates
server's AS. The route server uses pCount of zero to not increase signatures per client including its own AS in the BGPsec_Path and the
the effective AS hop count. target ASes, see 2.2.2 of [I-D.ietf-idr-ix-bgp-route-server]. The
route server uses pCount of zero to not increase the effective AS hop
count.
If it is known that a BGPsec neighbor is not a transparent route If it is known that a BGPsec neighbor is not a transparent route
server, and the router provides a knob to disallow a received pCount server, and the router provides a knob to disallow a received pCount
(prepend count, zero for transparent route servers) of zero, that (prepend count, zero for transparent route servers) of zero, that
knob SHOULD be applied. Routers should default to this knob knob SHOULD be applied. Routers should disallow pCount 0 by default.
disallowing pCount 0.
To prevent exposure of the internals of BGP Confederations [RFC5065], To prevent exposure of the internals of BGP Confederations [RFC5065],
a BGPsec speaker which is a Member-AS of a Confederation MUST NOT a BGPsec speaker which is a Member-AS of a Confederation MUST NOT
sign updates sent to another Member-AS of the same Confederation. sign updates sent to another Member-AS of the same Confederation.
8. Notes 8. Notes
For protection from attacks replaying BGP data on the order of a day For protection from attacks replaying BGP data on the order of a day
or longer old, re-keying routers with new keys (previously) or longer old, re-keying routers with new keys (previously)
provisioned in the RPKI is sufficient. For one approach, see provisioned in the RPKI is sufficient. For one approach, see
skipping to change at page 7, line 10 skipping to change at page 6, line 50
As a router must evaluate certificates and ROAs which are time As a router must evaluate certificates and ROAs which are time
dependent, routers' clocks MUST be correct to a tolerance of dependent, routers' clocks MUST be correct to a tolerance of
approximately an hour. approximately an hour.
If a router has reason to believe its clock is seriously incorrect, If a router has reason to believe its clock is seriously incorrect,
e.g. it has a time earlier than 2011, it SHOULD NOT attempt to e.g. it has a time earlier than 2011, it SHOULD NOT attempt to
validate incoming updates. It SHOULD defer validation until it validate incoming updates. It SHOULD defer validation until it
believes it is within reasonable time tolerance. believes it is within reasonable time tolerance.
Servers should provide time service, such as [RFC5905], to client Operators should deploy servers that provide time service, such as
routers. [RFC5905], to client routers.
9. Security Considerations 9. Security Considerations
The major security considerations for the BGPsec protocol are The major security considerations for the BGPsec protocol are
described in [I-D.ietf-sidr-bgpsec-protocol]. described in [I-D.ietf-sidr-bgpsec-protocol].
10. IANA Considerations 10. IANA Considerations
This document has no IANA Considerations. This document has no IANA Considerations.
 End of changes. 21 change blocks. 
52 lines changed or deleted 46 lines changed or added

This html diff was produced by rfcdiff 1.45. The latest version is available from http://tools.ietf.org/tools/rfcdiff/