[95513] in North American Network Operators' Group
Re: ICMP unreachables, code 9,10,13
daemon@ATHENA.MIT.EDU (Roland Dobbins)
Wed Mar 28 19:22:53 2007
In-Reply-To: <20070328225740.GA2663@mozart.cs.colostate.edu>
From: Roland Dobbins <rdobbins@cisco.com>
Date: Wed, 28 Mar 2007 16:14:17 -0700
To: nanog <nanog@merit.edu>
Errors-To: owner-nanog@merit.edu
On Mar 28, 2007, at 3:57 PM, Christos Papadopoulos wrote:
> Responses with these codes seem to imply the presence of a firewall.
> Is this assumption correct or are these codes meaningless?
Not just firewalls - ACLs on routers, too.
A common practice is to either turn off sending of unreachables or to
at least rate-limit them to preserve CPU on the router.
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