Upload
dooley
View
44
Download
0
Embed Size (px)
DESCRIPTION
Dean Cheng ([email protected]) Mohamed Boucadair ([email protected]) 79 th IETF Beijing. Routing IPv4-Embedded IPv6 Packets draft-cheng-ospf-ipv4-embedded-ipv6-routing-01. Some Terminologies. - PowerPoint PPT Presentation
Citation preview
Dean Cheng ([email protected])
Mohamed Boucadair ([email protected])
79th IETF Beijing
Routing IPv4-Embedded IPv6 Packets
draft-cheng-ospf-ipv4-embedded-ipv6-routing-01
Some Terminologies IPv4-Embedded IPv6 address
Denotes an IPv6 address which contains an embedded 32-bit IPv4
address constructed according to the rules defined in:
draft-ietf-behave-address-format-10 IPv4-Embedded IPv6 packets
IPv6 packets with destination addresses as IPv4-Embedded IPv6
addresses
AFBR Address Family Border Router (RFC5565) Refers to a border router which is located at the boundary of an IPv6-
only network and an IPv4-only network
The Problem
ASBR
IPv6
IPv6
IPv6 backbone
IPv4
IPv6
IPv4
IPv4ASBR
AFBR
AFBR
AFBR
? ?
?
Softwire Mesh (RFC5565) Approach
ASBR
IPv6
IPv6
IPv6 backbone
IPv4
IPv6
IPv4
IPv4ASBR
AFBR
AFBR
AFBR
•AFTRs exchange IPv4 reachability using BGP-MP•Tunnels established between AFTRs full-mesh•IPv4 packets transported in tunnels
OSPFv3 MT/MI Approach
ASBR
IPv6
IPv6
IPv6 backbone
IPv4
IPv6
IPv4
IPv4ASBR
AFBR
AFBR
AFBR
•AFBRs advertise IPv4-Embedded IPv6 addresses into the partial IPv6 backbone•A separate routing table for routing IPv4-Embedded IPv6 packets.
Scenarios where OSPFv3 approach useful
Running BGP not feasible on some AFTRs. Tunnel based forwarding not feasible
IPv4
IPv4
CPE
IPv6 Network
IPv4
CPE
CPE
CPE
CPE
CPE
CPE
ICXF
ICXFAFTR
AFTR
AFTR
ICXF
IPv6
IPv6
http://tools.ietf.org/html/draft-boucadair-dslite-interco-v4v6-04
Dual-Stack
DS-Lite
Mechanisms for separate routing table
Use OSPFv3 multi-instance mechanism Reference: RFC5838 Instantiate a separate instance for IPv4-Embedded
unicast IPv6 routing
Use OSPFv3 multi-topology mechanism Reference: http://tools.ietf.org/html/draft-ietf-ospf-mt-ospfv3-03.txt Configure interfaces for IPv4-Embedded unicast IPv6 routing
Advertising IPv4-Embedded IPv6 Routes
IPv4-Embedded IPv6 addresses would be advertised by AFBR
into IPv6 network as AS External LSA per OSPFv3(RFC5340) A single OSPFv3 AS External LSA carries one or more IPv4-
Embedded IPv6 addresses and prefixes By default, the metric is type-1 metric
Added to the intra-AS path for OSPFv3 routes calculation
May also be set to type-2 metric (by provisioning at AFBR) External metric may be exact the same unit as in IPv4 network
Forwarding IPv4-Embedded IPv6 Packets
Arriving packets with IPv4-Embedded IPv6 addresses are forwarded
along on IPv4-Embedded IPv6 topology. Packet header translation
According to http://tools.ietf.org/html/draft-ietf-behave-v6v4-xlate-23
Address translation According to draft-ietf-behave-address-format-10 IPv6 prefix
Well known IPv6 prefix 64::FF9B::/96, or ISP-specific IPv6 prefix
MTU handling Recommendation – AFTR to run PMTU (RFC1981.txt)
An issue for discussion In Section 2.6 of RFC5838
IPv4 address is located in the first 32-bit of the Forwarding Address field in AS-external LSA, with the remaining bits set to zero.
In this draft IPv4-Embedded IPv6 address encoded according to:
draft-ietf-behave-address-format-10 Question for the WG:
How to resolve this issue?
Next Step … Authors would like to solicit comments with discussion on
mailing list at this time If there is enough interest, we’ll propose to move this I-D as
a working group document