* Jeroen Massar > That is, if you have 6PE (IPv4 LSP) in your network routers might send > an ICMPv6 message from the IPv6-Mapped-IPv4 address. > > And as :::ffff:0.0.0.0/96 should not be in anybody's BGP table, it will > fail uRPF. > > Is anybody aware of a knob that can force for instance the loopback > address to be used on these boxes?
AIUI, the P routers in a network using 6PE might not have IPv6 addresses on them at all, not even on the loopback interface. If that's the case, there are three options that I can see: 1) enable core hiding, or 2) don't emit ICMPv6 errors at all, or 3) use an IPv4-mapped address as the source of the ICMPv6 errors. All of these constitute ways of breaking traceroute, although only #3 has a slight chance of actually relaying some useful information back to the person performing the traceroute. So IMHO it's the best option. Tore
