Hi All,
From my point of view, I think the midpoint protection is necessary in the SRv6
network deployment, and this technology is also relatively mature. I hope to
promote it as soon as possible.
In order to comply with RFC8200, it is recommended to restrict the
implementation of midpoint protection only on endpoint nodes, and not on
transit nodes.
Best Regards
Yisong
发件人: Huzhibo
时间: 2023/03/08(星期三)14:59
收件人: RTGWG;ipv6;spring;
主题: [spring] Comments Summary about SRv6 Midpoint Protection
Hi folks:
Based on the discussions held at the 115th IETF meeting, we summarized the
comments related to SRv6 midpoint protection, and then let's see how this
document can be further move ahead.
Q: how does SRv6 Midpoint protection differentiate the condition the route is
not present vs. link down? IPv6 prefix not advertised, or not link down?
A: SRv6 Midpoint Protection does not distinguish between Link Down and Node
Down. Assume that the Node is Down to maximize the protection scope.
Q: In SRv6, Some function maybe executed at Failure node, maybe accounting or
rewrite? SRv6 midpoint protection may miss the execution of some necessary
functions.like Security.
A: A mechanism is needed to indicate whether an endpoint can be bypassed or
not. [I-D.li-rtgwg-enhanced-ti-lfa] provides method to determine whether enable
SRv6 midpoint protection or not by defining a “no bypass” flag. which has been
updated in the document.
Q: Here we are handling 2 times failure (One layer-3 adjacency interface and
another primary interface), in all other cases we only handle one
failure.Better to restrict to handling of one failure.
A: layer-3 adjacency interface and primary interface may be the same interface.
Therefore, It must be processed.
Q: When the repair node is a transit node, it may be against RFC 8200 which
won’t allow transit node to modify SRH.
A: Only endpoint node can process SRH, Therefore, only endpoint nodes can
perform midpoint protection. This complies with RFC 8200,.which has been
updated in the document.
Q:Only endpoint node perform midpoint protection depends on IGP convergence in
some case.
A: Only when loose paths depend on IGP convergence, To comply with RFC 8200 .We
can only prohibit the execution SRv6 Midpoint protection on the transit node.
However, the IGP convergence performance is much better than that of SRv6
Policy rerouting.
Thanks
Zhibo Hu
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