I'd like to draw your attention to a talk that will be given this morning in 
homenet. The context is:

http://datatracker.ietf.org/doc/draft-baker-rtgwg-src-dst-routing-use-cases
http://tools.ietf.org/html/draft-baker-rtgwg-src-dst-routing-use-cases
  "Requirements and Use Cases for Source/Destination Routing", Fred Baker,
  2013-08-13

http://datatracker.ietf.org/doc/draft-xu-homenet-traffic-class
http://tools.ietf.org/html/draft-xu-homenet-traffic-class
  "Traffic Class Routing Protocol in Home Networks", Mingwei Xu, Shu Yang,
  Jianping Wu, Fred Baker, 2013-10-21

http://datatracker.ietf.org/doc/draft-xu-homenet-twod-ip-routing
http://tools.ietf.org/html/draft-xu-homenet-twod-ip-routing
  "Two Dimensional-IP Routing Protocol in Home Networks", Mingwei Xu, Shu
  Yang, Jianping Wu, Dan Wang, 2013-08-22

http://datatracker.ietf.org/doc/draft-baker-ipv6-ospf-dst-src-routing
http://tools.ietf.org/html/draft-baker-ipv6-ospf-dst-src-routing
  "IPv6 Source/Destination Routing using OSPFv3", Fred Baker, 2013-08-28

http://datatracker.ietf.org/doc/draft-ietf-ospf-ospfv3-lsa-extend
http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-lsa-extend
  "OSPFv3 LSA Extendibility", Acee Lindem, Sina Mirtorabi, Abhay Roy, Fred
  Baker, 2013-10-15

I had breakfast this morning with Shu Yang, who has been writing Quagga code 
for several years in the course of his PHd. He first implemented a 
source/destination model, reported on in draft-xu-homenet-twod-ip-routing, 
which was an MTR scheme. He tells me he found that very complex. He also 
listened to my talk in homenet around draft-baker-fun-routing-class, and has 
now implemented (if I understand him correctly) 
draft-ietf-ospf-ospfv3-lsa-extend and draft-baker-ipv6-ospf-dst-src-routing. 
The FIB implementation has a limitation: the source prefixes must be disjoint. 
However, given that, he has two FIB implementations, one of which has separate 
FIBs for each source prefix in play including ::/0 (so if there are M prefixes 
in the network, M+1 FIBs), and one of which is a single hierarchical M-Trie 
that looks up the destination and then the source. He has tested the code in 
simulation; the next step is testing in live networks.

Examples of use cases are generally around multi-prefix campus networks. There 
is a security use case that could be of value; at IETF 87, George Michaelson of 
APNIC reported on ULAs seen in his darknet. The short report is that he sees a 
fair bit of traffic with a ULA source address on the backbone. An interesting 
potential use of source/destination routing would counter that, and perhaps 
mitigate the need for ISP BCP 38 if generally deployed; in a case where a 
network is using a ULA and a global prefix (e.g., is not multihomed but has two 
prefixes, one of which is intended to only be used within its network), the 
default route to the network egress would use the global prefix as a source, 
and as a result traffic sent outside the network with a ULA source prefix would 
in effect have no route. The network could literally only emit traffic from its 
correct prefix.

I think this is relevant to the discussion of 
        draft-baker-rtgwg-src-dst-routing-use-cases
        draft-ietf-ospf-ospfv3-lsa-extend
        draft-baker-ipv6-ospf-dst-src-routing
        draft-baker-ipv6-isis-dst-src-routing

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