From owner-freebsd-net Sat Nov 11 23: 9:50 2000 Delivered-To: freebsd-net@freebsd.org Received: from overlord.e-gerbil.net (e-gerbil.net [207.91.110.247]) by hub.freebsd.org (Postfix) with ESMTP id AEA0437B479 for ; Sat, 11 Nov 2000 23:09:47 -0800 (PST) Received: by overlord.e-gerbil.net (Postfix, from userid 1001) id EB00AE4F0C; Sun, 12 Nov 2000 02:09:27 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by overlord.e-gerbil.net (Postfix) with ESMTP id D4310E4F0B; Sun, 12 Nov 2000 02:09:27 -0500 (EST) Date: Sun, 12 Nov 2000 02:09:27 -0500 (EST) From: "Richard A. Steenbergen" To: achilov@granch.ru Cc: freebsd-net@freebsd.org Subject: Re: Traceroute and UDP port 33434 In-Reply-To: <3A0E399A.DF69446D@sentry.granch.ru> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Sun, 12 Nov 2000, Rashid N. Achilov wrote: > I have encountered a strange problem - when I deny UDP port 33434, > traceroute refuses to trace...Can the traceroute use the UDP port 33434? The default unix traceroute uses UDP probes destined to supposidly "unused" ports. This probe starts at 33434 (32768+666 :P) and increments once with each probe. The default behavior is 3 probes per hop (per TTL increment), with a maximium of 30 hops, which means the standard unix traceroute will target UDP ports 33434-33524. The traceroute program knows there is another hop when it receives a TTL Exceed, and knows it has reached the end of the trace when it receives a Dest Unreachable for those ports. If something is listening on those ports, the traceroute will fail. With FreeBSD traceroute, the parameter you're looking for to change this default base is "-p ". HTH -- Richard A Steenbergen http://www.e-gerbil.net/humble PGP Key ID: 0x138EA177 (67 29 D7 BC E8 18 3E DA B2 46 B3 D8 14 36 FE B6) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message