From owner-freebsd-security Fri May 10 8:41:13 2002 Delivered-To: freebsd-security@freebsd.org Received: from sub21-156.member.dsl-only.net (sub21-156.member.dsl-only.net [63.105.21.156]) by hub.freebsd.org (Postfix) with ESMTP id 0DAFB37B403 for ; Fri, 10 May 2002 08:41:08 -0700 (PDT) Received: from sub21-156.member.dsl-only.net (freebsd.localhost.localdomain [127.0.0.1]) by sub21-156.member.dsl-only.net (8.11.6/8.11.6) with SMTP id g4AFkrp76185; Fri, 10 May 2002 08:47:06 -0700 (PDT) (envelope-from nkinkade@dsl-only.com) Date: Fri, 10 May 2002 08:46:53 -0700 From: Nathan Kinkade To: Sam Drinkard Cc: security@freebsd.org Subject: Re: Second request Talk ports/sockets Message-Id: <20020510084653.51d1ba8e.nkinkade@dsl-only.com> In-Reply-To: <3CDBCDFC.75062339@vortex.wa4phy.net> References: <3CDBCDFC.75062339@vortex.wa4phy.net> X-Mailer: Sylpheed version 0.7.4claws (GTK+ 1.2.10; i386-portbld-freebsd4.5) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Fri, 10 May 2002 09:41:16 -0400 Sam Drinkard wrote: > Since tightening up the firewall, my talk (from internal, not network) > is broken. I can't seem to figure out what ucp/tcp port(s) to open to > allow the talk utility to work. Looking at the source code didn't > help much either, but reference to sockets was mentioned. Once a user > logs in, does the talk utility not use the localhost address for > connections? The port for talk is 517. The port for ntalk is 518. I first found this out by launching ethereal (a network protocol analyzer that's in the ports collection). Then I attempted to launch a talk session with a non-existent host just to see some traffic. A quick review of the captured packets showed that my machine was attempting to communicate using ntalk on UDP port 518. I then did a quick search on Google for 'ntalk tcp port number'. The very first returned hit revealed the following. talk 517/tcp like tenex link, but across # machine - unfortunately, doesn't # use link protocol (this is actually # just a rendezvous port from which a # tcp connection is established) talk 517/udp like tenex link, but across # machine - unfortunately, doesn't # use link protocol (this is actually # just a rendezvous port from which a # tcp connection is established) ntalk 518/tcp ntalk 518/udp Further, a quick browse through /etc/services revealed exactly the same text as above. Presumably that's where the site got the information in the first place. There are plenty of ways to figure out information like this....it just requires that you think about it for a minute. The Google search engine is invaluable...and then again, as demonstrated above, often the info lies right on your own computer. Hope this helps. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message