Restricting ICMP

Mark admin at
Mon Aug 11 17:28:42 PDT 2003

----- Original Message ----- 
From: "Mark" <admin at>
To: <freebsd-questions at>
Sent: Tuesday, August 12, 2003 2:23 AM
Subject: Restricting ICMP

> Hello,
> Is there a way I can use ipfw to disallow ICMP from anyone, but
> root? (FreeBSD 4.7R) I tried this:
> ${fwcmd} -q add 4 allow icmp from any to any icmptype 0,3,8,11 in
> via ${outside}
> ${fwcmd} -q add 4 allow icmp from any to any uid root
> ${fwcmd} -q add 4 deny log icmp from any to any
> But that, obviously, does not do what I want it to, as it keeps
> denying everything going out. It may not even be possible to
> restrict ICMP that way, but it never hurts to ask. :)

Sorry for the addendum; but I was not entirely clear. I want to restrict
*outgoing* ICMP (traceroute and such) to anyone, but root.

- Mark

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