nanog mailing list archives

Re: ICMP unreachables, code 9,10,13


From: Roland Dobbins <rdobbins () cisco com>
Date: Wed, 28 Mar 2007 16:14:17 -0700



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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Roland Dobbins <rdobbins () cisco com> // 408.527.6376 voice

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