On Mon, 30 May 2016, Randy Bush wrote:
of course, simpletons such as i would desire the source of the time exceeded message to be A. after all, this is the interface to which i sent the icmp with the TTL to expire.
I agree 100%, and I'd venture to guess that most of the people running networks expect it to work like you describe.
cursory research and talking with C & J seem to indicate that they do what i want not what some folk have interpreted 1812 to mean. at least on some models.
is anyone seeing the dreaded rfc1812 behavior in a citable fashion? how common is it?
I have been told that there were versions of IOS XR that stopped doing what people wanted, people screamed, and then it's now back to the behaviour that you describe. In RFC1812 2.2.7 there is talk about router-id. When reading that I think it is generic enough to work for IPv6 as well? Another thing I've seen: People number their links with ULAs. ICMP error messages (including PTBs) are then sent from the router using the ULA address. This is obviously a disaster since that PTB sourced from ULA address is going to be BCP38:ed (hopefully). What's the interaction here with choosing a source address for the ICMP error message from something with the same RFC6724 label as the ICMP error message is being sent to? -- Mikael Abrahamsson email: swmike@swm.pp.se