On September 24, 2022 at 5:23:05 PM, Les Ginsberg wrote:
Les: Hi! > I have given your comments regarding clearer guidance on what value to use > for router id more thought and tried to address this in V5 of the document > (recently posted). > > I introduced a new sub-section "Choosing the TE Router ID Value", discussing > how to choose the value for IPv4 and IPv6. > Subsequent sections now refer to this section. > > Note that V5 also addresses comments from: > > Rob Wilton > Eric Vyncke > Lars Eggert > Paul Wouters > > Let me know if you still have concerns. I still have the same questions: This is the new text from §3.1: 354 3.1. Choosing the TE Router ID Value 356 Subsequent sections specify advertisement of a TE Router ID value for 357 IPv4 and/or IPv6. This section defines how this value is chosen. 359 When advertising an IPv4 address as a TE Router ID, the address 360 SHOULD be identical to the value advertised in the Traffic 361 Engineering Router ID TLV [RFC5305]. In cases where the Traffic 362 Engineering Router ID is not advertised, the TE Router ID MAY be 363 identical to an IP Interface Address [RFC1195] advertised by the 364 originating IS. [] If the Traffic Engineering Router ID TLV is advertised, when is it ok for the Router ID to not be identical? Why is this behavior recommended and not required? I had originally asked: > > > Should the receiver of these TLVs take any action if the values are not > > > identical? > > > > [LES:] No. If the values are not required to be identical (which, without qualification or guidance means that the Router ID can take any other value), and no action is taken if they're not, then I'm at a loss as to why the setting would even be normatively indicated. The second part of the text makes it optional for the value to be identical to something else. Again, if optional then there is an even lower expectation that the value will be "identical to an IP Interface Address". I realize that there aren't too many other options and that there's a pretty good chance that an IP Interface Address will be chosen, regardless of what this document says -- but chance is not a way to guarantee interoperability nor something normative guidance should be based on. I also asked: > > > (2) §3.1: The requirement for the Router ID to be unique within the > > > flooding scope of the LSP has been removed. > > > > [LES:] We are not changing anything about TLV 134 (AKA TE Router ID ) . But > > given the multiple ways the field in the inter AS TLV can be filled in, it > > no longer seemed appropriate to make this statement. Given the language above (not required, optional, etc.), I can buy this statement. > > The need for uniqueness of the TE Router ID still exists - but it is the > > province of RFC 5305. This statement assumes that the Router ID in the Inter-AS Reachability TLV will be set to the value in TLV 134, but the text above doesn't require it. Also, rfc5305 doesn't mention anything about the TE router ID being unique -- did I miss it? Given the language above (not required, optional, etc.), it doesn't seem to matter whether the value is unique. 366 When advertising an IPv6 address as a TE Router ID, the address 367 SHOULD be identical to the value advertised in the IPv6 TE Router ID 368 TLV [RFC6119]. In cases where the IPv6 TE Router ID is not 369 advertised, the TE Router ID MAY be identical to a global IPv6 370 Interface Address advertised by the originating IS in a Link State 371 PDU using the IPv6 Intf. Addr TLV [RFC5308]. [] The same comments apply. Thanks! Alvaro. _______________________________________________ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
