Joe,
What draft-ietf-spring-srv6-network-programming proposes is to remove a
segment routing header (SRH) along the packet delivery path, before the
packet arrives at the final destination. They call it PSP.
Before, folks have also proposed to insert Extension Headers (EHs) while
packets are en-route to their intended destination, etc.
Thanks,
Fernando
On 27/2/20 20:21, Joe Touch wrote:
EH isn't a HBH option or extension.
Joe
On 2020-02-27 15:06, Fernando Gont wrote:
On 27/2/20 19:52, Joe Touch wrote:
FWIW - there are separable issues here:
- whether an IP header (or parts thereof) should be changed in transit
AFAICT, the answer has always been yes, but limited to the
hopcount/ttl in the base header and hop-by-hop options in the
options/extension headers.
- whether an IP header length can change in transit
I see no reason why it can't become smaller, but if it can become
larger then PMTUD and PLPMTUD don't work.
Besides AH (which obviously breaks), hosts typically try to validate
that the error messages they receive correspond to something they
actually sent.
EH removal breaks that.
--
Fernando Gont
SI6 Networks
e-mail: fgont@xxxxxxxxxxxxxxx
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