< draft-ietf-rtgwg-net2cloud-problem-statement-01.txt   draft-ietf-rtgwg-net2cloud-problem-statement-02.txt >
Network Working Group L. Dunbar Network Working Group L. Dunbar
Internet Draft A. Malis Internet Draft A. Malis
Intended status: Informational Futurewei Intended status: Informational Futurewei
Expires: Dec 2019 C. Jacquenet Expires: Dec 2019 C. Jacquenet
Orange Orange
M. Toy M. Toy
Verizon Verizon
June 5, 2019 June 17, 2019
Seamless Interconnect Underlay to Cloud Overlay Problem Statement Dynamic Networks to Hybrid Cloud DCs Problem Statement
draft-ietf-rtgwg-net2cloud-problem-statement-01 draft-ietf-rtgwg-net2cloud-problem-statement-02
Abstract Abstract
This document describes the problems that enterprises face today This document describes the problems that enterprises face today
when connecting their branch offices to dynamic workloads in third when connecting their branch offices to dynamic workloads in third
party data centers (a.k.a. Cloud DCs). party data centers (a.k.a. Cloud DCs).
It examines some of the approaches interconnecting cloud DCs with It examines some of the approaches interconnecting cloud DCs with
enterprises' on-premises DCs & branch offices. This document also enterprises' on-premises DCs & branch offices. This document also
describes some of the (network) problems that many enterprises face describes some of the network problems that many enterprises face
when they have workloads & applications & data split among hybrid when they have workloads & applications & data split among hybrid
data centers, especially for those enterprises with multiple sites data centers, especially for those enterprises with multiple sites
that are already interconnected by VPNs (e.g., MPLS L2VPN/L3VPN). that are already interconnected by VPNs (e.g., MPLS L2VPN/L3VPN).
Current operational problems are examined to determine whether there Current operational problems are examined to determine whether there
is a need to improve existing protocols or whether a new protocol is is a need to improve existing protocols or whether a new protocol is
necessary to solve them. necessary to solve them.
Status of this Memo Status of this Memo
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months and may be updated, replaced, or obsoleted by other documents months and may be updated, replaced, or obsoleted by other documents
at any time. It is inappropriate to use Internet-Drafts as at any time. It is inappropriate to use Internet-Drafts as
reference material or to cite them other than as "work in progress." reference material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html http://www.ietf.org/shadow.html
This Internet-Draft will expire on December 5, 2019. This Internet-Draft will expire on December 17, 2019.
Copyright Notice Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the Copyright (c) 2019 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
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warranty as described in the Simplified BSD License. warranty as described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction...................................................3 1. Introduction...................................................3
1.1. On the evolution of Cloud DC connectivity.................3 1.1. On the evolution of Cloud DC connectivity.................3
1.2. The role of SD-WAN techniques in Cloud DC connectivity....4 1.2. The role of SD-WAN techniques in Cloud DC connectivity....4
2. Definition of terms............................................4 2. Definition of terms............................................4
3. Current Practices in Interconnecting Enterprise Sites with Cloud 3. Current Practices in Interconnecting Enterprise Sites with Cloud
DCs...............................................................5 DCs...............................................................5
3.1. Interconnect to Cloud DCs.................................5 3.1. Multiple connection to workloads in a Cloud DC............5
3.2. Interconnect to Hybrid Cloud DCs..........................8 3.2. Interconnect to Hybrid Cloud DCs..........................7
3.3. Connecting workloads among hybrid Cloud DCs...............8 3.3. Connecting workloads among hybrid Cloud DCs...............8
4. Desired Properties for Networks that interconnect Hybrid Clouds9 4. Desired Properties for Networks that interconnect Hybrid Clouds9
5. Problems with MPLS-based VPNs extending to Hybrid Cloud DCs...10 5. Problems with MPLS-based VPNs extending to Hybrid Cloud DCs....9
6. Problem with using IPsec tunnels to Cloud DCs.................11 6. Problem with using IPsec tunnels to Cloud DCs.................11
6.1. Complexity of multi-point any-to-any interconnection.....12 6.1. Complexity of multi-point any-to-any interconnection.....11
6.2. Poor performance over long distance......................12 6.2. Poor performance over long distance......................12
6.3. Scaling Issues with IPsec Tunnels........................13 6.3. Scaling Issues with IPsec Tunnels........................12
7. Problems of Using SD-WAN to connect to Cloud DCs..............13 7. Problems of Using SD-WAN to connect to Cloud DCs..............13
7.1. SD-WAN among branch offices vs. interconnect to Cloud DCs13 7.1. SD-WAN among branch offices vs. interconnect to Cloud DCs13
8. End-to-End Security Concerns for Data Flows...................16 8. End-to-End Security Concerns for Data Flows...................16
9. Requirements for Dynamic Cloud Data Center VPNs...............16 9. Requirements for Dynamic Cloud Data Center VPNs...............16
10. Security Considerations......................................17 10. Security Considerations......................................17
Solution drafts resulting from this work will address security
concerns inherent to the solution(s), including both protocol
aspects and the importance (for example) of securing workloads in
cloud DCs and the use of secure interconnection mechanisms.......17
11. IANA Considerations..........................................17 11. IANA Considerations..........................................17
12. References...................................................17 12. References...................................................17
12.1. Normative References....................................17 12.1. Normative References....................................17
12.2. Informative References..................................17 12.2. Informative References..................................17
13. Acknowledgments..............................................18 13. Acknowledgments..............................................18
1. Introduction 1. Introduction
1.1. On the evolution of Cloud DC connectivity 1.1. On the evolution of Cloud DC connectivity
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L3VPNs. Then connecting to the cloud-hosted resources may not be L3VPNs. Then connecting to the cloud-hosted resources may not be
straightforward if the provider of the VPN service does not have straightforward if the provider of the VPN service does not have
direct connections to the corresponding cloud DCs. Under those direct connections to the corresponding cloud DCs. Under those
circumstances, the enterprise can upgrade the CPEs deployed in its circumstances, the enterprise can upgrade the CPEs deployed in its
various premises to utilize SD-WAN techniques to reach cloud various premises to utilize SD-WAN techniques to reach cloud
resources (without any assistance from the VPN service provider), or resources (without any assistance from the VPN service provider), or
wait for their VPN service provider to make new agreements with data wait for their VPN service provider to make new agreements with data
center providers to connect to the cloud resources. Either way has center providers to connect to the cloud resources. Either way has
additional infrastructure and operational costs. additional infrastructure and operational costs.
In addition, it is an uptrend with more enterprises instantiating In addition, more enterprises are moving towards hybrid cloud DCs,
their apps & workloads in different cloud DCs to maximize the i.e. owned or operated by different Cloud operators, to maximize the
benefits of geographical proximity, elasticity and special features benefits of geographical proximity, elasticity and special features
offered by different cloud DCs. offered by different cloud DCs.
1.2. The role of SD-WAN techniques in Cloud DC connectivity 1.2. The role of SD-WAN techniques in Cloud DC connectivity
This document discusses issues raised by the connection of This document discusses the issues associated with connecting
enterprise premises to third party data centers (a.k.a. Cloud DCs) enterprise to their workloads/applications instantiated in multiple
for reaching dynamic workloads. third-party data centers (a.k.a. Cloud DCs). Very often, the actual
Cloud DCs that host the workloads/applications can be transient. .
SD-WAN, initially launched to maximize bandwidths between locations SD-WAN, initially launched to maximize bandwidths between locations
by aggregating multiple paths managed by different service by aggregating multiple paths managed by different service
providers, has expanded to include flexible, on-demand, application- providers, has expanded to include flexible, on-demand, application-
based connections established over any networks to access dynamic based connections established over any networks to access dynamic
workloads in Cloud DCs. workloads in Cloud DCs.
As a consequence, this document discusses the use of SD-WAN As a consequence, this document discusses the use of SD-WAN
techniques as a means to improve enterprise-to-cloud DC techniques as a means to improve enterprise-to-cloud DC
connectivity. connectivity.
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Controller: Used interchangeably with SD-WAN controller to manage Controller: Used interchangeably with SD-WAN controller to manage
SD-WAN overlay path creation/deletion and monitoring the SD-WAN overlay path creation/deletion and monitoring the
path conditions between two or more sites. path conditions between two or more sites.
DSVPN: Dynamic Smart Virtual Private Network. DSVPN is a secure DSVPN: Dynamic Smart Virtual Private Network. DSVPN is a secure
network that exchanges data between sites without network that exchanges data between sites without
needing to pass traffic through an organization's needing to pass traffic through an organization's
headquarter virtual private network (VPN) server or headquarter virtual private network (VPN) server or
router. router.
Heterogeneous Cloud: applications & workloads split among Cloud DCs Heterogeneous Cloud: applications and workloads split among Cloud
owned & managed by different operators. DCs owned or managed by different operators.
Hybrid Clouds: Hybrid Clouds (usually plural) refer to enterprises Hybrid Clouds: Hybrid Clouds refers to an enterprise using its own
using their own premises DCs in addition to Cloud on-premises DCs in addition to Cloud services provided
services provided by multiple cloud operators. For by one or more cloud operators. (e.g. AWS, Azure,
example, an enterprise not only have applications Google, Salesforces, SAP, etc).
running in their own DCs, but also have applications
hosted in multiple third party cloud DCs ((AWS, Azure,
Google, Salesforces, SAP, etc). . ONUG also has a
notion of heterogeneous cloud, refers to enterprises
does not have its own DC, only uses services by 3rd
party cloud operators.
SD-WAN: Software Defined Wide Area Network. In this document, SD-WAN: Software Defined Wide Area Network. In this document,
"SD-WAN" refers to the solutions of pooling WAN "SD-WAN" refers to the solutions of pooling WAN
bandwidth from multiple underlay networks to get better bandwidth from multiple underlay networks to get better
WAN bandwidth management, visibility & control. When the WAN bandwidth management, visibility & control. When the
underlay networks are private networks, traffic can underlay networks are private networks, traffic can
traverse without additional encryption; when the traverse without additional encryption; when the
underlay networks are public, such as Internet, some underlay networks are public, such as Internet, some
traffic needs to be encrypted when traversing through traffic needs to be encrypted when traversing through
(depending on user provided policies). (depending on user provided policies).
VPC: Virtual Private Cloud. A service offered by Cloud DC VPC: Virtual Private Cloud. A service offered by Cloud DC
operators to allocate logically-isolated cloud operators to allocate logically-isolated cloud
resources, including compute, networking and storage. resources, including compute, networking and storage.
3. Current Practices in Interconnecting Enterprise Sites with Cloud DCs 3. Current Practices in Interconnecting Enterprise Sites with Cloud DCs
3.1. Interconnect to Cloud DCs 3.1. Multiple connection to workloads in a Cloud DC
Most Cloud operators offer some type of network gateway through Most Cloud operators offer some type of network gateway through
which an enterprise can reach their workloads hosted in the Cloud which an enterprise can reach their workloads hosted in the Cloud
DCs. For example, AWS (Amazon Web Services) offers the following DCs. For example, AWS (Amazon Web Services) offers the following
options to reach workloads in AWS Cloud DCs: options to reach workloads in AWS Cloud DCs:
- Internet gateway for any external entities to reach the - AWS Internet gateway allows communication between instances in
workloads hosted in AWS Cloud DC via the Internet. AWS VPC and the internet.
- Virtual gateway (vGW) where IPsec tunnels [RFC6071] are - AWS Virtual gateway (vGW) where IPsec tunnels [RFC6071] are
established between an enterprise's own gateway and AWS vGW, so established between an enterprise's own gateway and AWS vGW, so
that the communications between those gateways can be secured that the communications between those gateways can be secured
from the underlay (which might be the public Internet). from the underlay (which might be the public Internet).
- Direct Connect, which allows enterprises to purchase direct - AWS Direct Connect, which allows enterprises to purchase direct
connect from network service providers to get a private leased connect from network service providers to get a private leased
line interconnecting the enterprises gateway(s) and the AWS line interconnecting the enterprises gateway(s) and the AWS
Direct Connect routers. Via Direct Connect, an AWS Transit Direct Connect routers. In addition, an AWS Transit Gateway can
Gateway can be used to interconnect multiple VPCs in different be used to interconnect multiple VPCs in different Availability
Availability Zones. Zones.
CPEs at one Enterprise branch office are connected to the Internet As an example, some branch offices of an enterprise can connect to
to reach AWS's vGW via IPsec tunnels. Other ports of such CPEs are over the Internet to reach AWS's vGW via IPsec tunnels. Other branch
connected to AWS DirectConnect via a private network (without any offices of the same enterprise can connect to AWS DirectConnect via
encryption). a private network (without any encryption). ). It is important for
enterprises to be able to observe the specific behaviors when
connected by different connections.
Figure below shows an example of some tenants' workloads are
accessible via a virtual router connected by AWS Internet Gateway;
some are accessible via AWS vGW, and others are accessible via AWS
Direct Connect. The vR1 can have its own IPsec capability for secure
tunnel over the internet to bypass paying additional price for the
IPsec features provided by AWS vGW. Some tenants can deploy separate
virtual routers to connect to internet traffic and to traffic from
the secure channels from vGW and DirectConnect, e.g. vR1 & vR2.
Others may have one virtual router connecting to both types of
traffic. Customer Gateway can be customer owned router or ports
physically connected to AWS Direct Connect GW.
+------------------------+ +------------------------+
| ,---. ,---. | | ,---. ,---. |
| (TN-1 ) ( TN-2)| | (TN-1 ) ( TN-2)|
| `-+-' +--+ `-+-' | | `-+-' +---+ `-+-' |
| +----|vR|-----+ | | +----|vR1|----+ |
| ++-+ | | ++--+ |
| | +-+----+ | | +-+----+
| | /Internet\ For External | | /Internet\ For External
| +-------+ Gateway +---------------------- | +-------+ Gateway +----------------------
| \ / to reach via Internet | \ / to reach via Internet
| +-+----+ | +-+----+
| | | |
+------------------------+
+------------------------+
| ,---. ,---. | | ,---. ,---. |
| (TN-1 ) ( TN-2)| | (TN-1 ) ( TN-2)|
| `-+-' +--+ `-+-' | | `-+-' +---+ `-+-' |
| +----|vR|-----+ | | +----|vR2|----+ |
| ++-+ | | ++--+ |
| | +-+----+ | | +-+----+
| | / virtual\ For IPsec Tunnel | | / virtual\ For IPsec Tunnel
| +-------+ Gateway +---------------------- | +-------+ Gateway +----------------------
| \ / termination | | \ / termination
| +-+----+ | | +-+----+
| | | | |
+------------------------+
+------------------------+
| ,---. ,---. |
| (TN-1 ) ( TN-2)|
| `-+-' +--+ `-+-' |
| +----|vR|-----+ |
| ++-+ |
| | +-+----+ +------+ | | +-+----+ +------+
| | / \ For Direct /customer\ | | / \ For Direct /customer\
| +-------+ Gateway +----------+ gateway | | +-------+ Gateway +----------+ gateway |
| \ / Connect \ / | \ / Connect \ /
| +-+----+ +------+ | +-+----+ +------+
| | | |
+------------------------+ +------------------------+
Figure 1: Examples of Cloud DC connections. Figure 1: Examples of Multiple Cloud DC connections.
3.2. Interconnect to Hybrid Cloud DCs 3.2. Interconnect to Hybrid Cloud DCs
According to Gartner, by 2020 "hybrid will be the most common usage Hybrid will be the most common usage of the cloud as more
of the cloud" as more enterprises see the benefits of integrating enterprises see the benefits of integrating public and private cloud
public and private cloud infrastructures. However, enabling the infrastructures. However, enabling the growth of hybrid cloud
growth of hybrid cloud deployments in the enterprise requires fast deployments in the enterprise requires fast and safe interconnection
and safe interconnection between public and private cloud services. between public and private cloud services.
For an enterprise to connect to applications & workloads hosted in For an enterprise to connect to applications & workloads hosted in
multiple Cloud DCs, the enterprise can use IPsec tunnels established multiple Cloud DCs, the enterprise can use IPsec tunnels established
over the Internet or a (virtualized) leased line service to connect over the Internet or a (virtualized) leased line service to connect
its on-premises gateways to each of the Cloud DC's gateways, virtual its on-premises gateways to each of the Cloud DC's gateways, virtual
routers instantiated in the Cloud DCs, or any other suitable design routers instantiated in the Cloud DCs, or any other suitable design
(including a combination thereof). (including a combination thereof).
Some enterprises prefer to instantiate their own virtual Some enterprises prefer to instantiate their own virtual
CPEs/routers inside the Cloud DC to connect the workloads within the CPEs/routers inside the Cloud DC to connect the workloads within the
Cloud DC. Then an overlay path is established between customer Cloud DC. Then an overlay path is established between customer
gateways to the virtual CPEs/routers for reaching the workloads gateways to the virtual CPEs/routers for reaching the workloads
inside the cloud DC. inside the cloud DC.
3.3. Connecting workloads among hybrid Cloud DCs 3.3. Connecting workloads among hybrid Cloud DCs
There are multiple approaches to interconnect workloads among There are multiple approaches to interconnect workloads among
different Cloud DCs: different Cloud DCs:
- Utilize Cloud DC provided transit gateways, which usually does a) Utilize Cloud DC provided transit gateways.
not work if Cloud DCs are owned and managed by different Cloud b) Hairpin all the traffic through the customer gateway, or
providers. c) Establish direct tunnels among different VPCs (Virtual Private
- Hairpin all the traffic through the customer gateway, which
creates additional transmission delay & incurs cost when
exiting Cloud DCs, or
- Establish direct tunnels among different VPCs (Virtual Private
Clouds) via client's own virtual routers instantiated within Clouds) via client's own virtual routers instantiated within
Cloud DCs. DMVPN (Dynamic Multipoint Virtual Private Network) Cloud DCs. DMVPN (Dynamic Multipoint Virtual Private Network)
or DSVPN (Dynamic Smart VPN) techniques can be used to or DSVPN (Dynamic Smart VPN) techniques can be used to
establish direct Multi-point-to-Point or multi-point-to multi- establish direct Multi-point-to-Point or multi-point-to multi-
point tunnels among those client's own virtual routers. point tunnels among those client's own virtual routers.
DMVPN & DSVPN use NHRP (Next Hop Resolution Protocol) [RFC2735] so Approach a) usually does not work if Cloud DCs are owned and managed
that spoke nodes can register their IP addresses & WAN ports with by different Cloud providers.
the hub node. The IETF ION (Internetworking over NBMA (non-broadcast
multiple access) WG standardized NHRP for connection-oriented NBMA Approach b) creates additional transmission delay plus incurring
network (such as ATM) network address resolution more than two cost when exiting Cloud DCs.
decades ago.
For the Approach c), DMVPN or DSVPN use NHRP (Next Hop Resolution
Protocol) [RFC2735] so that spoke nodes can register their IP
addresses & WAN ports with the hub node. The IETF ION
(Internetworking over NBMA (non-broadcast multiple access) WG
standardized NHRP for connection-oriented NBMA network (such as ATM)
network address resolution more than two decades ago.
There are many differences between virtual routers in Public Cloud There are many differences between virtual routers in Public Cloud
DCs and the nodes in an NBMA network. NHRP & DSVPN are not cannot be DCs and the nodes in an NBMA network. NHRP cannot be used for
used for registering virtual routers in Cloud DCs unless an registering virtual routers in Cloud DCs unless an extension of such
extension of such protocols is developed for that purpose. Other protocols is developed for that purpose. Therefore, DMVPN and/or
protocols such as BGP can be used, as described in [BGP-SDWAN]. DSVPN cannot be used directly for connecting workloads in hybrid
Cloud DCs.
Other protocols such as BGP can be used, as described in [BGP-
SDWAN].
4. Desired Properties for Networks that interconnect Hybrid Clouds 4. Desired Properties for Networks that interconnect Hybrid Clouds
The networks that interconnect hybrid cloud DCs must address the The networks that interconnect hybrid cloud DCs must address the
following requirements: following requirements:
- High availability at any time, whatever the duration of the - High availability to access all workloads in the desired cloud
connection to the cloud DC. DCs.
Many enterprises include cloud infrastructures in their Many enterprises include cloud infrastructures in their
disaster recovery strategy, e.g., by enforcing periodic backup disaster recovery strategy, e.g., by enforcing periodic backup
policies within the cloud, or by running backup applications in policies within the cloud, or by running backup applications in
the Cloud, etc. Therefore, the connection to the cloud DCs may the Cloud, etc. Therefore, the connection to the cloud DCs may
not be permanent, but rather needs to be on-demand. not be permanent, but rather needs to be on-demand.
- Global reachability from different geographical zones, thereby - Global reachability from different geographical zones, thereby
facilitating the proximity of applications as a function of the facilitating the proximity of applications as a function of the
end users' location, to improve latency. end users' location, to improve latency.
- Elasticity and mobility, to instantiate additional applications - Elasticity: prompt connection to newly instantiated
at Cloud DCs when end-users' usages increase and shut down applications at Cloud DCs when end-users' usages increase and
applications at locations when there are fewer end-users. prompt release of connection after applications at locations
being removed when demands change.
Some enterprises have front-end web portals running in cloud Some enterprises have front-end web portals running in cloud
DCs and database servers in their on-premises DCs. Those Front- DCs and database servers in their on-premises DCs. Those Front-
end web portals need to be reachable from the public Internet. end web portals need to be reachable from the public Internet.
The backend connection to the sensitive data in database The backend connection to the sensitive data in database
servers hosted in the on-premises DCs might need secure servers hosted in the on-premises DCs might need secure
connections. connections.
- Scalable security management. IPsec is commonly used to - Scalable security management. IPsec is commonly used to
interconnect cloud gateways with CPEs deployed in the interconnect cloud gateways with CPEs deployed in the
enterprise premises. For enterprises with a large number or enterprise premises. For enterprises with a large number or
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One of the main drivers for moving workloads into the cloud is One of the main drivers for moving workloads into the cloud is
the widely available cloud DCs at geographically diverse the widely available cloud DCs at geographically diverse
locations, where apps can be instantiated so that they can be locations, where apps can be instantiated so that they can be
as close to their end-users as possible. When the user base as close to their end-users as possible. When the user base
changes, the applications may be migrated to a new cloud DC changes, the applications may be migrated to a new cloud DC
location closest to the new user base. location closest to the new user base.
- Most of the cloud DCs do not expose their internal networks, so - Most of the cloud DCs do not expose their internal networks, so
the MPLS-based VPNs can only reach Cloud DC's Gateways, not to the MPLS-based VPNs can only reach Cloud DC's Gateways, not to
the workloads hosted inside. the workloads hosted inside. Even with AWS DirectConnect, the
connection only reaches the AWS DirectConnect Gateway.
- Many cloud DCs use an overlay to connect their gateways to the - Extensive usage of Overlay by Cloud DCs:
workloads located inside the DC. There is currently no standard
that specifies the interworking between the Cloud Overlay and Many cloud DCs use an overlay to connect their gateways to the
the enterprise' existing underlay networks. One of the workloads located inside the DC. There is currently no standard
characteristics of overlay networks is that some of the WAN that specifies the interworking between the Cloud Overlay and the
rd ports of the edge nodes connect to 3 party networks. There is enterprise' existing underlay networks. One of the
therefore a need to propagate WAN port information to remote characteristics of overlay networks is that some of the WAN ports rd of the edge nodes connect to 3 party networks. There is
rd authorized peers in 3 party network domains in addition to therefore a need to propagate WAN port information to remote rd authorized peers in 3 party network domains in addition to route
route propagation. Such an exchange cannot happen before propagation. Such an exchange cannot happen before communication
communication between peers is properly secured. between peers is properly secured.
Another roadblock is the lack of a standard way to express and Another roadblock is the lack of a standard way to express and
enforce consistent security policies for workloads that not only use enforce consistent security policies for workloads that not only use
virtual addresses, but in which are also very likely hosted in virtual addresses, but in which are also very likely hosted in
different locations within the Cloud DC [RFC8192]. The current VPN different locations within the Cloud DC [RFC8192]. The current VPN
path computation and bandwidth allocation schemes may not be path computation and bandwidth allocation schemes may not be
flexible enough to address the need for enterprises to rapidly flexible enough to address the need for enterprises to rapidly
connect to dynamically instantiated (or removed) workloads and connect to dynamically instantiated (or removed) workloads and
applications regardless of their location/nature (i.e., third party applications regardless of their location/nature (i.e., third party
cloud DCs). cloud DCs).
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description, let's call such CPEs asymmetrically-managed CPEs). description, let's call such CPEs asymmetrically-managed CPEs).
- Cloud DCs may have different entry points (or devices) with one - Cloud DCs may have different entry points (or devices) with one
entry point that terminates a private direct connection (based entry point that terminates a private direct connection (based
upon a leased line for example) and other entry points being upon a leased line for example) and other entry points being
devices terminating the IPsec tunnels, as shown in Figure 2. devices terminating the IPsec tunnels, as shown in Figure 2.
Therefore, the SD-WAN design becomes asymmetric. Therefore, the SD-WAN design becomes asymmetric.
+------------------------+ +------------------------+
| ,---. ,---. | | ,---. ,---. |
| (TN-1 ) ( TN-2)| | (TN-1 ) ( TN-2)| TN: Tenant applications/workloads
| `-+-' +---+ `-+-' | | `-+-' +---+ `-+-' |
| +----|vR1|----+ | | +----|vR1|----+ |
| ++--+ | | ++--+ |
| | +-+----+ | | +-+----+
| | /Internet\ One path via | | /Internet\ One path via
| +-------+ Gateway +---------------------+ | +-------+ Gateway +---------------------+
| \ / Internet \ | \ / Internet \
| +-+----+ \ | +-+----+ \
+------------------------+ \ +------------------------+ \
\ \
+------------------------+ native traffic \ +------------------------+ native traffic \
| ,---. ,---. | without encryption| | ,---. ,---. | without encryption|
| (TN-3 ) ( TN-4)| | | (TN-3 ) ( TN-4)| |
| `-+-' +--+ `-+-' | | +------+ | `-+-' +--+ `-+-' | | +------+
| +----|vR|-----+ | +------+ CPE | | +----|vR|-----+ | +--+ CPE |
| ++-+ | | +------+ | ++-+ | | +------+
| | +-+----+ | | | +-+----+ |
| | / virtual\ One path via IPsec Tunnel | | | / virtual\ One path via IPsec Tunnel |
| +-------+ Gateway +-------------------------- + | +-------+ Gateway +-------------------------- +
| \ / Encrypted traffic over| | \ / Encrypted traffic over|
| +-+----+ public network | | +-+----+ public network |
+------------------------+ | +------------------------+ |
| |
+------------------------+ | +------------------------+ |
| ,---. ,---. | Native traffic | | ,---. ,---. | Native traffic |
| (TN-5 ) ( TN-6)| without encryption | | (TN-5 ) ( TN-6)| without encryption |
| `-+-' +--+ `-+-' | over secure network| | `-+-' +--+ `-+-' | over secure network|
| +----|vR|-----+ | | | +----|vR|-----+ | |
| ++-+ | | | ++-+ | |
| | +-+----+ +------+ | | | +-+----+ +------+ |
| | / \ Via Direct /customer\ | | | / \ Via Direct /customer\ |
| +-------+ Gateway +----------+ gateway |-----+ | +-------+ Gateway +----------+ gateway |-----+
| \ / Connect \ / | \ / Connect \ /
| +-+----+ +------+ | +-+----+ +------+
+------------------------+ +------------------------+ Customer GW has physical connection to AWS GW.
Figure 2: Different Underlays to Reach Cloud DC Figure 2: Different Underlays to Reach Cloud DC
8. End-to-End Security Concerns for Data Flows 8. End-to-End Security Concerns for Data Flows
When IPsec tunnels established from enterprise on-premises CPEs When IPsec tunnels established from enterprise on-premises CPEs
are terminated at the Cloud DC gateway where the workloads or are terminated at the Cloud DC gateway where the workloads or
applications are hosted, some enterprises have concerns regarding applications are hosted, some enterprises have concerns regarding
traffic to/from their workload being exposed to others behind the traffic to/from their workload being exposed to others behind the
data center gateway (e.g., exposed to other organizations that data center gateway (e.g., exposed to other organizations that
skipping to change at page 18, line 14 skipping to change at page 18, line 14
[RFC4664] L. Andersson and E. Rosen, "Framework for Layer 2 Virtual [RFC4664] L. Andersson and E. Rosen, "Framework for Layer 2 Virtual
Private Networks (L2VPNs)", Sept 2006. Private Networks (L2VPNs)", Sept 2006.
[BGP-SDWAN] L. Dunbar, et al. "BGP Extension for SDWAN Overlay [BGP-SDWAN] L. Dunbar, et al. "BGP Extension for SDWAN Overlay
Networks", draft-dunbar-idr-bgp-sdwan-overlay-ext-03, Networks", draft-dunbar-idr-bgp-sdwan-overlay-ext-03,
work-in-progress, Nov 2018. work-in-progress, Nov 2018.
13. Acknowledgments 13. Acknowledgments
Many thanks to Ignas Bagdonas, Michael Huang, Liu Yuan Jiao, Many thanks to Chris Bowers, Ignas Bagdonas, Michael Huang, Liu Yuan
Katherine Zhao, and Jim Guichard for the discussion and Jiao, Katherine Zhao, and Jim Guichard for the discussion and
contributions. contributions.
Authors' Addresses Authors' Addresses
Linda Dunbar Linda Dunbar
Futurewei Futurewei
Email: Linda.Dunbar@huawei.com Email: Linda.Dunbar@futurewei.com
Andrew G. Malis Andrew G. Malis
Futurewei Futurewei
Email: agmalis@gmail.com Email: agmalis@gmail.com
Christian Jacquenet Christian Jacquenet
Orange Orange
Rennes, 35000 Rennes, 35000
France France
Email: Christian.jacquenet@orange.com Email: Christian.jacquenet@orange.com
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