Internet DRAFT - draft-zmw-bess-tunnel-vpn
draft-zmw-bess-tunnel-vpn
BESS Zheng. Zhang
Internet-Draft ZTE Corporation
Intended status: Standards Track Shaowen. Ma
Expires: April 25, 2019 Juniper
Cui. Wang
Matrium Technologies
October 22, 2018
Use of IP Tunnels In IP VPNs
draft-zmw-bess-tunnel-vpn-00
Abstract
This document updates [RFC6513], [RFC6514] and
[I-D.ietf-idr-tunnel-encaps] to provide additional details about
using GRE tunnels for IP VPN, and using IP tunnels for Multicast VPN
(MVPN).
Requirements Language
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 RFC2119.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on April 25, 2019.
Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Specification . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1. GRE Considered as a Tunnel Type Whose Encapsulation
Includes VNI field . . . . . . . . . . . . . . . . . . . 3
3.2. Attach Tunnel Encap Attribute to MVPN PMSI/Leaf A-D
Routes . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 4
7. Normative References . . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Terminology
This document uses terminologies defined in [RFC6513], [RFC6514].
2. Introduction
[RFC4364] specifies protocol and procedures for providing IP Virtual
Private Network (IP VPN) service using BGP signaling and MPLS data
plane, often referred to as BGP/MPLS VPN. Along with the great
success of BGP/MPLS VPN, use of IP tunneling instead of MPLS has been
growing significantly, especially in Data Centers or where MPLS
infrastructure is not available.
IP tunnels typically include GRE, VXLAN, VXLAN-GPE, and NVGRE. Both
VXLAN and NVGRE are targeted at Layer 2 Overlay services and the
payload after the VXLAN or NVGRE header is Ethernet. For GRE
[RFC2784] and VXLAN-GPE, the payload could be either IP or Ethernet
or others. [I-D.ietf-idr-tunnel-encaps] specifies how these tunnels
can be used for VPNs, and [RFC6513] describes how GRE tunnels can be
used for Multicast VPNs (MVPN).
However, existing documents do not fully cover some deployment
scenarios as listed below.
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o Use of GRE tunnel for IP VPN: GRE tunnel is currently not listed
as one of the three tunnel types whose encapsulation header
includes a Virtual Network Identifier (VNI), even though an
optional key in GRE header can be used as a VNI. As a result,
currently there is no document specifies the use of GRE tunnel for
IP VPN unicast, while it may be desired in certain situations.
For example, multicast GRE tunnels are already widely used for
MVPNs. If IP tunnels are preferred over MPLS tunnels for unicast,
then it is better to use GRE (vs. VXLAN-GPE) for unicast as well
as for multicast. Another reason to use GRE instead of VXLAN-GPE
is that in certain public provider networks UDP packets are more
susceptible to packet losses.
o While [RFC6513] has descriptive text (section 12.1.1) on using
unicast GRE tunnel for Ingress Replication, [RFC6514] (the
specification companion of [RFC6513]) only covers MPLS tunnels.
o To use IP tunnels for Ingress Replication in MVPN, appropriate
Tunnel Encap Attribute (TEA) needs to be attached relevant MVPN
PMSI/Leaf A-D routes, however that is declared as out of scope for
[I-D.ietf-idr-tunnel-encaps].
3. Specification
This document specifies the details for missing coverage (as desribed
above) in existing documentations.
3.1. GRE Considered as a Tunnel Type Whose Encapsulation Includes VNI
field
This document updates Section "8. Use of Virtual Network Identifiers
and Embedded Labels when Imposing a Tunnel Encapsulation" of
[I-D.ietf-idr-tunnel-encaps] as following:
o A GRE tunnel whose encapsulation does not set the K bit in the GRE
header is considered as without a Virtual Network Identifier
Field, and section 8.1 applies.
o A GRE tunnel whose encapsulation does set the K bit in the GRE
header is considered as having a Virtual Network Identifier Field,
and section 8.2 applies. When applying the rules in section 8.2,
the condition "the TLV identifying the tunnel contains an
Encapsulation sub-TLV whose V bit is set" is considered met as
long as the TEA includes a GRE Encapsulation Sub-TLV.
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3.2. Attach Tunnel Encap Attribute to MVPN PMSI/Leaf A-D Routes
If IP tunnels are used for MVPN Ingress Replication, a TEA SHOULD be
attached to MVPN Inclusive-PMSI A-D routes and Leaf A-D routes to
specify the IP tunnel used for the originating router to receive
traffic. The label field in the A-D route's PMSI Tunnel Attribute
(PTA) is set to the VNI assigned by the originating router. When an
ingress router sends traffic, the label value in the PTA of
Inclusive-PMSI or Leaf A-D route originated from the receiving router
is copied into the VNI field of the tunnel encapsulation header.
Note that in case of GRE tunnel, the VNI field is the Key field in
the GRE header and the K bit MUST be set.
4. IANA Considerations
This document makes no requests for IANA action.
5. Security Considerations
There is no further security requirements in this document.
6. Acknowledgement
The authors would like to thank Jeffrey Zhang for his valuable
discussion and suggestion.
7. Normative References
[I-D.ietf-idr-tunnel-encaps]
Rosen, E., Patel, K., and G. Velde, "The BGP Tunnel
Encapsulation Attribute", draft-ietf-idr-tunnel-encaps-10
(work in progress), August 2018.
[RFC2784] Farinacci, D., Li, T., Hanks, S., Meyer, D., and P.
Traina, "Generic Routing Encapsulation (GRE)", RFC 2784,
DOI 10.17487/RFC2784, March 2000,
<https://www.rfc-editor.org/info/rfc2784>.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
2006, <https://www.rfc-editor.org/info/rfc4364>.
[RFC6513] Rosen, E., Ed. and R. Aggarwal, Ed., "Multicast in MPLS/
BGP IP VPNs", RFC 6513, DOI 10.17487/RFC6513, February
2012, <https://www.rfc-editor.org/info/rfc6513>.
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[RFC6514] Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP
Encodings and Procedures for Multicast in MPLS/BGP IP
VPNs", RFC 6514, DOI 10.17487/RFC6514, February 2012,
<https://www.rfc-editor.org/info/rfc6514>.
Authors' Addresses
Zheng(Sandy) Zhang
ZTE Corporation
EMail: zzhang_ietf@hotmail.com
Shaowen Ma
Juniper
EMail: mashaowen@gmail.com
Cui(Linda) Wang
Matrium Technologies
Australia
EMail: lindawangjoy@gmail.com
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