The MPLS WG Archive

[schultz@io.iol.unh.edu]

Hello,

I have a question about the object orders.

In RFC 2205, section 3.1 states:
An implementation should create messages with the objects in the order
shown here, but accept the objects in any permissible order.

In sections 3.1.3 and 3.1.4, the standard asserts that the INTEGRITY
object must immediately follow the common header.

RFC 2961 also dictates strict ordering rules for the MESSAGE_ID object.

However, RFC 3209 notes: "The ordering of these objects is not important,
so an implementation MUST be prepared to accept objects in any order."

A strict interpretation of this statement would assume that if a device
disregards the object ordering rules, it can still interoperate.

What is the correct behavior for the following situation:

An LSR receives a Path or Resv message that violates the ordering rules.
Does it accept the message and allow the LSP tunnel to form?  Or does it
send an error message as recommended in Appendix B of RFC 2205?

Thanks,
-Ben