Re: General question on rfc1918

On Tue, 13 Nov 2007, Drew Weaver wrote:

Is it to be expected to see rfc1918 src'd packets coming from transit carriers?

Yes. Any ISP which uses RFC1918 on "internal" links may generate various ICMP error packets (e.g. traceroute/TTL expire, PMTU discovery/Fragmentation required, etc) from router interfaces which have RFC1918 addresses for transit traffic. Some people filter them anyway, and get "*"'s in traceroutes and PMTU weirdness. #include "old debate about using RFC1918 addresses on transit links" #include "other old debate about filtering stuff in backbones or edge"