the O UDP checksum proposal obsoletes all the today deployed nodes
which check them (so all hosts I know and perhaps a lot of routers
too)
OK, so what are the other options for encapsulating a packet in a
IPv6
packet?
Um, surely, routers are not specified to validate layer-4
checksums for transit traffic?!?
Right, or have to build pseudo-headers in a contiguous buffer with the
*entire* data packet to calculate such a UDP checksum.
Let's look at this another way? As I understood it, UDP 0 would
be used by LISP encapsulating/decapsulating devices.
Right. But on the ETR, it is spec'ed to "ignore" checksums because
there are NATs that rewrite UDP checksum fields regardless if the NAT
receives the packet with a zero or non-zero UDP checksum.
If some random (non-LISP encap/decap) host by mistake received a
0 UDP packet, it would be dropped, which should do no harm.
As would a router (acting as a hsot) that is not doing LISP.
In practical terms, only LISP encap/decap devices would need to
be modified to accept 0 UDP packets under some specific rule /
circumstance, as an exception to the general rule.
Right (modulo what I wrote above about ignoring UDP checksums on the
decapsulator).
The only thing which would prevent this would be one of
conformance to the letter of the original spec, which apparently
bans 0 UDP checksums.
Right.
So what's so bad about that?
Good question.
Dino
Regards,
- Håvard
_______________________________________________
lisp mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/lisp
--------------------------------------------------------------------
IETF IPv6 working group mailing list
[email protected]
Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6
--------------------------------------------------------------------
