Hi Sasha, Thanks for your valuable question!
Since a Path Segment is just designed to identify an SR path, if the Path Segment label is the BoS label, the network protocol of the packet should be the same as the one implied by the last label of the SR path. That means, no matter through signaling or configuration, when install a Path Segment label, the implicit network protocol can deduced from the last label of the SR path. Hope this clarify the question, or maybe you have other suggestions. Best regards, Mach From: Alexander Vainshtein [mailto:[email protected]] Sent: Thursday, July 12, 2018 6:00 PM To: [email protected] Cc: [email protected] Subject: A question about Path Segment draft Dear colleagues, One of the issues I've raised during my Early RTG-DIR review<https://datatracker.ietf.org/doc/review-ietf-spring-segment-routing-mpls-13-rtgdir-early-vainshtein-2018-06-10/> of the SR-MPLS<https://tools.ietf.org/html/draft-ietf-spring-segment-routing-mpls-14> draft dealt the way in which identity of the network protocol of the packet can be inferred when the label that represents some segment ID happens to be the bottom-of-stack label. The Editors' response<https://www.ietf.org/mail-archive/web/spring/current/msg03877.html> was that for labels representing Prefix and Adjacency SIDs, the network protocol of such a packet is always either Ipv4 and IPv6. For Prefix SIDs this is obvious and for Adjacency SIDs IPv4 vs. IPv6 is indicated by the F-Flag in the corresponding IS-IS TLV (or its analogs for OSPF). This is also applicable for Binding SID because it refers to a specific prefix (or a range of prefixes from the same family). >From my POV this response is sufficient in the context of the SR-MPLS. >However, it does not help in the case of Path Segments introduced with your >draft. One use case for the label representing a Path Segment being BoS is LSP Ping (RFC 8029) for Segment Routing (RFC 8287) since both IPv4 and IPv6 packets can follow the BoS label in LSP Ping. It is not even clear whether packets immediately following the Path Segment label that is BoS can be neither IPv4 nor IPv6. Your clarification of this point would be highly appreciated. Regards, Sasha Office: +972-39266302 Cell: +972-549266302 Email: [email protected]<mailto:[email protected]> ___________________________________________________________________________ This e-mail message is intended for the recipient only and contains information which is CONFIDENTIAL and which may be proprietary to ECI Telecom. If you have received this transmission in error, please inform us by e-mail, phone or fax, and then delete the original and all copies thereof. ___________________________________________________________________________
_______________________________________________ spring mailing list [email protected] https://www.ietf.org/mailman/listinfo/spring
