Re: [spring] Question about SRv6 Insert function

[li zhenqiang <[e-mail]>]

Hello Robert,

What you said is correct. But what the documents want to do is not what you said. Please see my email raised this discussion.

End.B6.Insert specified in draft-ietf-spring-srv6-network-programming-01 will insert a new SRH in the received IPv6 packet, which results in two SRHs in one IPv6 packet. It is contradict with RFC8200 that says Each extension header should occur at most once, except for the Destination Options header.

In draft-voyer-6man-extension-header-insertion-06, an intermediate node executes the insert function to implement a sub-50 milliseconds FRR operation upon link failure. It is contradict with RFC8200 that says Extension headers (except for the Hop-by-Hop Options header) are not processed, inserted, or deleted by any node along a packet’s delivery path, until the packet reaches the node (or each of the set of nodes, in the case of multicast) identified in the Destination Address field of the IPv6 header.

Best Regards,
Zhenqiang Li
________________________________
[e-mail]

From: Robert Raszuk<mailto:[e-mail]>
Date: 2019-09-05 16:28
To: Fernando Gont<mailto:[e-mail]>
CC: Ron Bonica<mailto:rbonica=[e-mail]>; [e-mail]<mailto:[e-mail]>; [e-mail]<mailto:[e-mail]>; Ole Troan<mailto:[e-mail]>; Suresh Krishnan<mailto:[e-mail]>; draft-voyer-6man-extension-header-insertion<mailto:[e-mail]>; draft-ietf-spring-srv6-network-programming<mailto:[e-mail]>
Subject: Re: [spring] Question about SRv6 Insert function
Hi Fernando,

If folks want to do EH insertion, the #1 step is to publish a document
that updates RFC8200 such that the "EHs must not be inserted..." is
replaced with something else or eliminated.

I have very basic question to close this debate.

Is IP encapsulation of the packet allowed by IPv6 specs or not ?

If it is I see no issue with any documents you quote since when I add a new IPv6 header I can add any field to it. Moreover when I see myself as destination address of the packet RFC8200 verbatim allows to add, delete or modify EHs. I hope you agree with it.

If IP encapsulation is forbidden by IPv6 RFCs please provide a quote and ref.

Many thx,
R.