Subject: Re: How do I traceroute through ipf?
To: David Laight <email@example.com>
From: Darren Reed <firstname.lastname@example.org>
Date: 01/31/2002 01:43:26
In some email I received from David Laight, sie wrote:
> My attempts to traceroute get stomped by my ipf configuration:
> % traceroute www.dilbert.com
> Jan 16 22:35:24 snowdrop ipmon: 22:35:24.160418 ppp0
> @150:4 b 18.104.22.168,33099 -> 22.214.171.124,33435 PR udp len 20 10240
> Unfortunately this seems to be a udp packet from a random port to a
> random port - and I don't want the filters open that far. I presume the
> destination port is really irrelevant and maybe port 9 (discard) would
> be more appropriate?
Go read about how traceroute works. Port 9 is not more appropriate.
Or use the ICMP version of traceroute.