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Re: [OT] Pinging and traceroute



On Sun, Jul 29, 2001 at 02:04:26AM -0500, Hall Stevenson wrote:
> 
> Any ideas why I'm unable to run a traceroute to an IP address without
> first pinging it ?? If I try and trace a site, it does little to

I am not sure here.

> I do have an IPTABLES firewall running. Pinging a site does nothing to
> the firewall's logs. Using traceroute does. This is the relevant
> firewall rule, I think:

traceroute doesn't use ICMP (at least, not primarily).  It uses UDP.  I
assume you're filtering UDP somehow?  traceroute runs on a high port
(somewhere in the 30000+ range).  Here's a quote from the traceroute man
page:
	This  program  attempts  to  trace  the route an IP packet
       would follow to some internet host by launching UDP  probe
       packets with a small ttl (time to live) then listening for
       an ICMP "time exceeded" reply from a  gateway.


noah

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