In your previous mail you wrote:
Discussing one implementation, a possible source of ambiguity in RFC2461
came up.
RFC2461 discusses that next-hops must be on-link.
=> this is an obvious requirement.
However, section 8 on redirect basically requires:
- routers know each others' link-local addresses (not an issue from
hosts' perspective, just use routing protocols or other mechanisms)
=> routers may know each others' global addresses too, mainly
through prefix-infos with the R bit set (so this R bit is useful
outside mobile IPv6 and should be added in a RFC 2461bis) or through
external routing protocols. BTW when routers don't know each others'
global addresses you can't use standard network management tools
(i.e., SNMP with standard MIBs) to perform a topology discovery
(i.e., a network map) because you can't go further than the local links.
This issue was signaled by Jean-Luc Richier many years ago but was
never solved...
- hosts are able to verify that the redirect comes from the link-local
address the host is currently using as its next-hop
The latter is a bit problematic. How could the host know this in the case
where the next-hop has been configured using e.g. a _global_ (but on-link)
address?
What's the deal here?
=> I agree RFC 2461 expects the next-hop is always characterized by its
link-local address (as it is on a shared link it always has one).
There are some implementations which enforce the use of link-local
addresses but I agree that global addresses are not forbidden, or
the use of more than one link-local address... BTW I don't believe
a host is required to redirect its packets.
Regards
[EMAIL PROTECTED]
PS: I've looked at BSD (mine old stack and KAME) codes: the source
of the redirect is compared with the "gateway" field of the route to
the redirected destination: if they don't match the redirect is rejected.
--------------------------------------------------------------------
IETF IPng Working Group Mailing List
IPng Home Page: http://playground.sun.com/ipng
FTP archive: ftp://playground.sun.com/pub/ipng
Direct all administrative requests to [EMAIL PROTECTED]
--------------------------------------------------------------------
