Alain,

As a first comment, the document is lacking a discussion of the
implications of having the BR use its anycast address as the source
address for the packets it relays.

Take for example the case of two BRs A and B that configure the
same IP anycast address, and a CE router C within the 6rd domain.
If BR A forwards packets toward C, but the packets are  lost in the SP
network, any resulting ICMPs could just as easily flow back through
BR B instead of A. Then, if the ICMPs don't contain enough information
for translation, BR B has no way to send a translated message back
to the original source and a black hole can result.

A solution to this would be to have BR's use their unicast address as
the source instead of an anycast address. In that case, CE router
C simply needs a way to discover the unicast addresses of all BRs
in the domain that configure the same anycast address. Such discovery
could be via the DHCP option, via DNS resolution of a FQDN, etc.

Fred
[email protected]

________________________________
From: [email protected] [mailto:[email protected]] On Behalf Of 
Durand, Alain
Sent: Monday, February 22, 2010 1:43 PM
To: softwires; DHC WG
Cc: David Ward; Ole Troan
Subject: [dhcwg] SOFTWIRE working group last call on 6rd

All -

We'd like to announce the softwire WG LC on the 6rd technology. I've copied 
both SOFTWIRE and DHC mailing lists and solicit comments from both groups of 
experts. The draft is here:

http://www.ietf.org/internet-drafts/draft-ietf-softwire-ipv6-6rd-07.txt

Please reply with comments to this thread by 2010.03.08 at 1700 PST

Thanks

- Alain
_______________________________________________
Softwires mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/softwires
_______________________________________________
Softwires mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/softwires

Reply via email to