As Pekka already pointed out, all the three methods are provided as examples. The draft mandates the rate limiting by saying:
"an IPv6 node MUST limit the rate of ICMPv6 error messages it sends"
and then it provides examples by saying:
"There are a variety of ways of implementing the rate-limiting function, for example:"
It's worth noting that the change in this section from RFC2463 (which icmp-v3-** will be replacing) was to add token bucket to the list of examples. RFC2463 only lists the timer and bandwidth methods. I think most people agree that token bucket is preferable.
So I don't think we will be doing anything bad by removing the bad examples.
The Timer-based method does create an significant operational problem i.e. it breaks traceroute.
I would be happy if the text was expanded to say that token bucket is the preferred approach and describe the limitations of the other two. I think this would give the people implementing ICMPv6 the guidance they need to build a rate-limiting function that is appropriate for their implementation.
Bob
-------------------------------------------------------------------- IETF IPv6 working group mailing list [EMAIL PROTECTED] Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
