On 10-May-2007, at 11:38, George V. Neville-Neil wrote:
At Thu, 10 May 2007 09:50:01 -0400,
Brian Haberman wrote:
The sentence could be modified in :
"Compliant IPv6 hosts and routers MUST NOT process RH0 in packets
addressed to them. Those packets MUST be dropped without further
processing. In particular, the value of the Segments Left field
MUST not be considered."
This is much clearer and easier to implement.
Though I am not a router vendor I am the person who has to handle this
on FreeBSD. I like the above sentence as well.
The above sentences far more closely resemble what I meant to write,
compared to the text that actually appeared in the draft :-)
I note that KAME's response to this is similar, but it's not clear to
me that it's precisely identical: a patched KAME implementation
treats the type 0 routing header as an unknown routing header
(according to <http://www.kame.net/newsletter/20070502/>). This
suggests to me that a patched KAME implementation will process a
datagram containing RH0, but that RH0 header(s) in the datagram will
not be acted upon. I would welcome corrections to my feeble
assumptions in this area (I have done no tests, nor read any source
code to confirm).
A packet containing RH0 presumably is intended not to be processed on
the system identified by the destination address field; if it was, no
RH0 would be present. This suggests to me that "MUST drop" is the
right thing, rather than "process as if RH0 was not there"; in
addition, if we assume that today any packet with RH0 is likely to be
malicious, any processing of a packet containing RH0 which has the
potential to result in backscatter seems like it should properly be
avoided.
Joe
--------------------------------------------------------------------
IETF IPv6 working group mailing list
[email protected]
Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6
--------------------------------------------------------------------
