Internet DRAFT - draft-xu-isis-encapsulation-cap
draft-xu-isis-encapsulation-cap
ISIS Working Group X. Xu, Ed.
Internet-Draft Huawei
Intended status: Standards Track B. Decraene, Ed.
Expires: April 17, 2017 Orange
R. Raszuk
Bloomberg LP
U. Chunduri
L. Contreras
Telefonica I+D
L. Jalil
Verizon
October 14, 2016
Advertising Tunnelling Capability in IS-IS
draft-xu-isis-encapsulation-cap-07
Abstract
Some networks use tunnels for a variety of reasons. A large variety
of tunnel types are defined and the ingress needs to select a type of
tunnel which is supported by the egress. This document defines how
to advertise egress tunnel capabilities in IS-IS Router Capability
TLV.
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 RFC 2119 [RFC2119].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 17, 2017.
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Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Advertising Encapsulation Capability . . . . . . . . . . . . 3
4. Tunnel Encapsulation Type . . . . . . . . . . . . . . . . . . 3
5. Tunnel Encapsulation Attribute . . . . . . . . . . . . . . . 5
5.1. Tunnel Parameters sub-TLV . . . . . . . . . . . . . . . . 5
5.2. Encapsulated Protocol sub-TLV . . . . . . . . . . . . . . 6
5.3. End Point sub-TLV . . . . . . . . . . . . . . . . . . . . 6
5.4. Color sub-TLV . . . . . . . . . . . . . . . . . . . . . . 6
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
6.1. IS-IS Router Capability . . . . . . . . . . . . . . . . . 6
6.2. IGP Tunnel Encapsulation Types Registry . . . . . . . . . 6
6.3. IGP Tunnel Encapsulation Attribute Types Registry . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 8
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction
Some networks use tunnels for a variety of reasons, such as:
o Partial deployment of MPLS-SPRING as described in
[I-D.xu-mpls-spring-islands-connection-over-ip], where IP tunnels
are used between MPLS-SPRING-enabled routers so as to traverse
non- MPLS routers.
o Partial deployment of MPLS-BIER as described in Section 6.9 of
[I-D.ietf-bier-architecture], where IP tunnels are used between
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MPLS-BIER-capable routers so as to traverse non MPLS-BIER
[I-D.ietf-bier-mpls-encapsulation] routers.
o Partial deployment of IPv6 (resp. IPv4) in IPv4 (resp. IPv6)
networks as described in [RFC5565], where IPvx tunnels are used
between IPvx-enabled routers so as to traverse non-IPvx routers.
o Remote Loop Free Alternate repair tunnels as described in
[RFC7490], where tunnels are used between the Point of Local
Repair and the selected PQ node.
The ingress needs to select a type of tunnel which is supported by
the egress. This document describes how to use IS-IS Router
Capability TLV to advertise the egress tunnelling capabilities of
nodes.
2. Terminology
This memo makes use of the terms defined in [RFC4971].
3. Advertising Encapsulation Capability
Routers advertises their supported encapsulation type(s) by
advertising a new sub-TLV of the IS-IS Router CAPABILITY TLV
[RFC4971], referred to as Encapsulation Capability sub-TLV. This
sub-TLV SHOULD NOT appear more than once within a given IS-IS Router
CAPABILITY TLV. The scope of the advertisement depends on the
application but it is recommended that it SHOULD be domain-wide. The
Type code of the Encapsulation Capability sub-TLV is TBD1, the Length
value is variable, and the Value field contains one or more Tunnel
Encapsulation Type sub-TLVs. Each Encapsulation Type sub-TLVs
indicates a particular encapsulation format that the advertising
router supports.
4. Tunnel Encapsulation Type
The Tunnel Encapsulation Type sub-TLV is structured as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tunnel Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Value |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Tunnel Type (1 octets): identifies the type of tunneling
technology being signaled. This document defines the following
types:
1. L2TPv3 over IP [RFC3931] : Type code=1;
2. GRE [RFC2784] : Type code=2;
3. Transmit tunnel endpoint [RFC5566] : Type code=3;
4. IPsec in Tunnel-mode [RFC5566] : Type code=4;
5. IP in IP tunnel with IPsec Transport Mode [RFC5566] : Type
code=5;
6. MPLS-in-IP tunnel with IPsec Transport Mode [RFC5566] : Type
code=6;
7. IP in IP [RFC2003] [RFC4213]: Type code=7;
8. VXLAN [RFC7348] : Type code=8;
9. NVGRE [RFC7637] : Type code=9;
10. MPLS [RFC3032] : Type code=10;
11. MPLS-in-GRE [RFC4023] : Type code=11;
12. VXLAN GPE [I-D.ietf-nvo3-vxlan-gpe] : Type code=12;
13. MPLS-in-UDP [RFC7510] : Type code=13;
14. MPLS-in-UDP-with-DTLS [RFC7510] : Type code=14;
15. MPLS-in-L2TPv3 [RFC4817] : Type code=15;
16. GTP: Type code=16;
Unknown types are to be ignored and skipped upon receipt.
Length (1 octets): unsigned integer indicating the total number of
octets of the value field.
Value (variable): zero or more Tunnel Encapsulation Attribute sub-
TLVs as defined in Section 5.
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5. Tunnel Encapsulation Attribute
The Tunnel Encapsulation Attribute sub-TLV is structured as as
follows:
+-----------------------------------+
| Sub-TLV Type (1 Octet) |
+-----------------------------------+
| Sub-TLV Length (1 Octet) |
+-----------------------------------+
| Sub-TLV Value (Variable) |
| |
+-----------------------------------+
Sub-TLV Type (1 octet): each sub-TLV type defines a certain
property about the tunnel TLV that contains this sub-TLV. The
following are the types defined in this document:
1. Encapsulation Parameters: sub-TLV type = 1; (See Section 5.1)
2. Encapsulated Protocol: sub-TLV type = 2; (See Section 5.2)
3. End Point: sub-TLV type = 3; (See Section 5.3)
4. Color: sub-TLV type = 4; (See Section 5.4)
Sub-TLV Length (1 octet): unsigned integer indicating the total
number of octets of the sub-TLV value field.
Sub-TLV Value (variable): encodings of the value field depend on
the sub-TLV type as enumerated above. The following sub-sections
define the encoding in detail.
Any unknown sub-TLVs MUST be ignored and skipped. However, if the
TLV is understood, the entire TLV MUST NOT be ignored just because it
contains an unknown sub-TLV.
If a sub-TLV is erroneous, this specific Tunnel Encapsulation MUST be
ignored and skipped. However, others Tunnel Encapsulations MUST be
considered.
5.1. Tunnel Parameters sub-TLV
This sub-TLV has its format defined in [RFC5512] under the name
Encapsulation sub-TLV.
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5.2. Encapsulated Protocol sub-TLV
This sub-TLV has its format defined in [RFC5512] under the name
Protocol Type.
5.3. End Point sub-TLV
The value field carries the Network Address to be used as tunnel
destination address.
If length is 4, the Address Family (AFI) is IPv4.
If length is 16, the Address Family (AFI) is IPv6.
5.4. Color sub-TLV
The valued field is a 4 octets opaque unsigned integer.
The color value is user defined and configured locally on the
routers. It may be used by the service providers to define policies.
6. IANA Considerations
6.1. IS-IS Router Capability
This document requests IANA to allocate a new code point from
registry IS-IS Router CAPABILITY TLV.
Value TLV Name Reference
----- ------------------------------------ -------------
TBD1 Tunnel Capabilities This document
6.2. IGP Tunnel Encapsulation Types Registry
This document requests IANA to create a new registry "IGP Tunnel
Encapsulation Types" with the following registration procedure:
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Registry Name: IGP Tunnel Encapsulation Type.
Value Name Reference
------- ------------------------------------------ -------------
0 Reserved This document
1 L2TPv3 over IP This document
2 GRE This document
3 Transmit tunnel endpoint This document
4 IPsec in Tunnel-mode This document
5 IP in IP tunnel with IPsec Transport Mode This document
6 MPLS-in-IP tunnel with IPsec Transport Mode This document
7 IP in IP This document
8 VXLAN This document
9 NVGRE This document
10 MPLS This document
11 MPLS-in-GRE This document
12 VXLAN-GPE This document
13 MPLS-in-UDP This document
14 MPLS-in-UDP-with-DTLS This document
15 MPLS-in-L2TPv3 This document
16 GTP This document
17-250 Unassigned
251-254 Experimental This document
255 Reserved This document
Assignments of Encapsulation Types are via Standards Action
[RFC5226].
6.3. IGP Tunnel Encapsulation Attribute Types Registry
This document requests IANA to create a new registry "IGP Tunnel
Encapsulation Attribute Types" with the following registration
procedure:
Registry Name: IGP Tunnel Encapsulation Attribute Types.
Value Name Reference
------- ------------------------------------ -------------
0 Reserved This document
1 Encapsulation parameters This document
2 Protocol This document
3 End Point This document
4 Color This document
5-250 Unassigned
251-254 Experimental This document
255 Reserved This document
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Assignments of Encapsulation Attribute Types are via Standards Action
[RFC5226].
7. Security Considerations
Security considerations applicable to softwires can be found in the
mesh framework [RFC5565]. In general, security issues of the tunnel
protocols signaled through this IGP capability extension are
inherited.
If a third party is able to modify any of the information that is
used to form encapsulation headers, to choose a tunnel type, or to
choose a particular tunnel for a particular payload type, user data
packets may end up getting misrouted, misdelivered, and/or dropped.
Security considerations for the base IS-IS protocol are covered in
[RFC1195].
8. Acknowledgements
This document is partially inspired by [RFC5512].
The authors would like to thank Carlos Pignataro and Karsten Thomann
for their valuable comments on this draft.
9. References
9.1. Normative References
[RFC1700] Reynolds, J. and J. Postel, "Assigned Numbers", RFC 1700,
DOI 10.17487/RFC1700, October 1994,
<http://www.rfc-editor.org/info/rfc1700>.
[RFC2003] Perkins, C., "IP Encapsulation within IP", RFC 2003,
DOI 10.17487/RFC2003, October 1996,
<http://www.rfc-editor.org/info/rfc2003>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC2784] Farinacci, D., Li, T., Hanks, S., Meyer, D., and P.
Traina, "Generic Routing Encapsulation (GRE)", RFC 2784,
DOI 10.17487/RFC2784, March 2000,
<http://www.rfc-editor.org/info/rfc2784>.
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[RFC3931] Lau, J., Ed., Townsley, M., Ed., and I. Goyret, Ed.,
"Layer Two Tunneling Protocol - Version 3 (L2TPv3)",
RFC 3931, DOI 10.17487/RFC3931, March 2005,
<http://www.rfc-editor.org/info/rfc3931>.
[RFC4213] Nordmark, E. and R. Gilligan, "Basic Transition Mechanisms
for IPv6 Hosts and Routers", RFC 4213,
DOI 10.17487/RFC4213, October 2005,
<http://www.rfc-editor.org/info/rfc4213>.
[RFC4971] Vasseur, JP., Ed., Shen, N., Ed., and R. Aggarwal, Ed.,
"Intermediate System to Intermediate System (IS-IS)
Extensions for Advertising Router Information", RFC 4971,
DOI 10.17487/RFC4971, July 2007,
<http://www.rfc-editor.org/info/rfc4971>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>.
9.2. Informative References
[I-D.ietf-bier-architecture]
Wijnands, I., Rosen, E., Dolganow, A., Przygienda, T., and
S. Aldrin, "Multicast using Bit Index Explicit
Replication", draft-ietf-bier-architecture-04 (work in
progress), July 2016.
[I-D.ietf-bier-mpls-encapsulation]
Wijnands, I., Rosen, E., Dolganow, A., Tantsura, J.,
Aldrin, S., and I. Meilik, "Encapsulation for Bit Index
Explicit Replication in MPLS Networks", draft-ietf-bier-
mpls-encapsulation-05 (work in progress), July 2016.
[I-D.ietf-nvo3-vxlan-gpe]
Kreeger, L. and U. Elzur, "Generic Protocol Extension for
VXLAN", draft-ietf-nvo3-vxlan-gpe-02 (work in progress),
April 2016.
[I-D.xu-mpls-spring-islands-connection-over-ip]
Xu, X., Raszuk, R., Chunduri, U., Contreras, L., and L.
Jalil, "Connecting MPLS-SPRING Islands over IP Networks",
draft-xu-mpls-spring-islands-connection-over-ip-00 (work
in progress), October 2016.
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[RFC1195] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
dual environments", RFC 1195, DOI 10.17487/RFC1195,
December 1990, <http://www.rfc-editor.org/info/rfc1195>.
[RFC3032] Rosen, E., Tappan, D., Fedorkow, G., Rekhter, Y.,
Farinacci, D., Li, T., and A. Conta, "MPLS Label Stack
Encoding", RFC 3032, DOI 10.17487/RFC3032, January 2001,
<http://www.rfc-editor.org/info/rfc3032>.
[RFC4023] Worster, T., Rekhter, Y., and E. Rosen, Ed.,
"Encapsulating MPLS in IP or Generic Routing Encapsulation
(GRE)", RFC 4023, DOI 10.17487/RFC4023, March 2005,
<http://www.rfc-editor.org/info/rfc4023>.
[RFC4817] Townsley, M., Pignataro, C., Wainner, S., Seely, T., and
J. Young, "Encapsulation of MPLS over Layer 2 Tunneling
Protocol Version 3", RFC 4817, DOI 10.17487/RFC4817, March
2007, <http://www.rfc-editor.org/info/rfc4817>.
[RFC5512] Mohapatra, P. and E. Rosen, "The BGP Encapsulation
Subsequent Address Family Identifier (SAFI) and the BGP
Tunnel Encapsulation Attribute", RFC 5512,
DOI 10.17487/RFC5512, April 2009,
<http://www.rfc-editor.org/info/rfc5512>.
[RFC5565] Wu, J., Cui, Y., Metz, C., and E. Rosen, "Softwire Mesh
Framework", RFC 5565, DOI 10.17487/RFC5565, June 2009,
<http://www.rfc-editor.org/info/rfc5565>.
[RFC5566] Berger, L., White, R., and E. Rosen, "BGP IPsec Tunnel
Encapsulation Attribute", RFC 5566, DOI 10.17487/RFC5566,
June 2009, <http://www.rfc-editor.org/info/rfc5566>.
[RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
L., Sridhar, T., Bursell, M., and C. Wright, "Virtual
eXtensible Local Area Network (VXLAN): A Framework for
Overlaying Virtualized Layer 2 Networks over Layer 3
Networks", RFC 7348, DOI 10.17487/RFC7348, August 2014,
<http://www.rfc-editor.org/info/rfc7348>.
[RFC7490] Bryant, S., Filsfils, C., Previdi, S., Shand, M., and N.
So, "Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)",
RFC 7490, DOI 10.17487/RFC7490, April 2015,
<http://www.rfc-editor.org/info/rfc7490>.
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[RFC7510] Xu, X., Sheth, N., Yong, L., Callon, R., and D. Black,
"Encapsulating MPLS in UDP", RFC 7510,
DOI 10.17487/RFC7510, April 2015,
<http://www.rfc-editor.org/info/rfc7510>.
[RFC7637] Garg, P., Ed. and Y. Wang, Ed., "NVGRE: Network
Virtualization Using Generic Routing Encapsulation",
RFC 7637, DOI 10.17487/RFC7637, September 2015,
<http://www.rfc-editor.org/info/rfc7637>.
Authors' Addresses
Xiaohu Xu (editor)
Huawei
Email: xuxiaohu@huawei.com
Bruno Decraene (editor)
Orange
Email: bruno.decraene@orange.com
Robert Raszuk
Bloomberg LP
Email: robert@raszuk.net
Uma Chunduri
Email: uma.chunduri@gmail.com
Luis M. Contreras
Telefonica I+D
Email: luismiguel.contrerasmurillo@telefonica.com
Luay Jalil
Verizon
Email: luay.jalil@verizon.com
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