ICMP Blocking Woes

Date: Tue, 30 Sep 2003 19:36:23 -0500
From: John Kristoff <jtk@depaul.edu>
Sender: owner-nanog@merit.edu

> > Wasn't this based upon the premise that gear should not return ICMP
> > errors as a result of ICMP packet input as a precaution against error
> > loops? ie said dodgy router did the _right_ thing?

> That would be disingenious. RFC1122 clearly lists which ICMP are error
> messages,

The following from W. Richard Stevens' archive presents some additional


But note the date of this (1988). Clearly, router vendors are handling
this much better today, in light of 1122. Today tracert almost works
as well as traceroute.