An Interface Identifier (ID) Hello Option for PIM
RFC 6395
Yes
No Objection
Note: This ballot was opened for revision 01 and is now closed.
(Adrian Farrel; former steering group member) Yes
(Jari Arkko; former steering group member) Yes
(Dan Romascanu; former steering group member) (was Discuss) No Objection
1. I suggest to mention also RFC 2863 as a reference for ifIndex. Both definitions (in 1213 and 2863) are valid, but 2863 is expressed in SMIv2 and has slight changes in semantics (not relevant for this work). 2. In Section 2.1 The Local Interface Identifier MUST be non-zero. The reason for this, is that some protocols may want to only optionally refer to an Interface using the Interface Identifier Hello option, and use the value of 0 to show that it is not referred to. Note that the value of 0 is not a valid ifIndex as defined in [RFC1213]. RFC 2863 defines the InterfaceIndexOrZero TC which allows exactly for the special semantics of value 0. One more reason to provide it as a reference.
(David Harrington; former steering group member) No Objection
ifIndex can change, especially on reboot or even during a hot swap, depending on vendor and model. Implementations/uers who choose ifIndex as an identifier should be aware of this lack of stability. Since ifIndex is mentioned as one choice of identifer, the document should point out the possibility of change.
(Pete Resnick; former steering group member) No Objection
(Peter Saint-Andre; former steering group member) No Objection
Because the Router Identifier and Local Interface Identifier are more than 8 bits long, please specify their byte order. Although network byte order (the most significant byte first) is almost universally used, there are some exceptions, so it is important to spell this out.
(Robert Sparks; former steering group member) No Objection
(Ron Bonica; former steering group member) No Objection
(Russ Housley; former steering group member) No Objection
(Sean Turner; former steering group member) No Objection
<a complete and utter nit> I'd reorder sections 2.1 and 2.2. I would have thought you'd of talked about the higher order bits first. This is obviously non-blocking. </a complete and utter nit>
(Stephen Farrell; former steering group member) No Objection
1st sentence of section 2: saying that this identifies the interface of a *neighboring* router is a tiny bit confusing, I suggest saying it identifies an interface on a router for that router's neighbors to use. Just checking: I'm guessing there's no need to do anything, but just in case - I imagine that ifIndex values are often sequential small integers and hence guessable and that the router identifier is often an IPv4 address for the router and hence known, so are there any possible ways to abuse the fact that anyone could easily guess an Interface ID?
(Stewart Bryant; former steering group member) No Objection
(Wesley Eddy; former steering group member) No Objection