New router feature - icmp error source-interface [was: icmp rpf]

Richard A Steenbergen ras at
Tue Sep 26 00:48:42 UTC 2006

On Mon, Sep 25, 2006 at 08:45:49PM -0400, John Curran wrote:
> At 9:22 AM -0400 9/25/06, Patrick W. Gilmore wrote:
> >
> >Who thinks it would be a "good idea" to have a knob such that ICMP error messages are always source from a certain IP address on a router?
> It certainly would beat the alternative of no response at all,
> but one would hope it wouldn't become common practice
> since it reduces the information returned (e.g. during a
> traceroute, you'd lose the sometimes useful information
> from in-addr about what particular interface was involved).

Personally I'd hope that if it was implemented, it would support mapping 
on a per-interface basis (especially for NSP use). That should in theory 
lead to even more accurate information, since each network would be 
capable of easily renumbering without impact, and managing their own DNS 
for every interface. Currently a great many PTRs are out of date because 
IP blocks supplied by peers, exchange points, or transit providers, are 
too much of a pain to keep updated when interfaces move etc.

Richard A Steenbergen <ras at>
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)

More information about the NANOG mailing list