[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [RRG] The use of UDP in LISP
On 11 dec 2007, at 22:19, Marshall Eubanks wrote:
I think that this will require a modification to (ugh!) RFC 2460 -
o Unlike IPv4, when UDP packets are originated by an IPv6 node,
the UDP checksum is not optional.
Dino Farinacci has suggested this text :
o When a IPv6 router is using a UDP header as part of a tunnel
it MAY compute a UDP checksum.
At the least AMT and LISP would require this, and I suspect that
there will be others.
This doesn't make me very happy. Within the limited scope of LISP it
could work, but in the more general case it's a trainwreck waiting to
happen because you can't know in advance if a receiver is going to
accept the missing checksums. Please see my previous message on the
subject, I think its pragmatic in both accommodating the desired IPv4
behavior and retaining compatibility with the IPv6 specs.
By the way: host NICs routinely handle IPv4 IP and TCP/UDP
checksumming. I suggest router vendors start adding the same logic to
their hardware, and in a somewhat more general way so that IPv6 can
also be supported, with additional headers between the IP and TCP/UDP
headers when present. This will avoid similar issues in the future.
to unsubscribe send a message to firstname.lastname@example.org with the
word 'unsubscribe' in a single line as the message text body.
archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg