Security Basics mailing list archives
Re: Blocking IRC Access
From: Tim Syratt <tims () syratt com>
Date: Tue, 18 Nov 2003 10:39:40 +1100 (EST)
Hi Mike, Jeff is correct. I run an IRC server that sits on a 10,000 user network and the amount of open proxies that are used as BNC's, particularly from within networks is incredible. I'd perhaps think about looking at your network, considering what you REALLY need your users to access.. Focus on each department individually and their needs, put it on paper and impliment (if you dont already) some VLANS with controlled access.. Perhaps even look at Cisco URT if you need to dynamically assign VLANs on login. You also need to look at your servers inside your lan, and make sure none of them can be used to bounce outside the firewall (proxy servers, http servers etc) on an obscure port and over to an IRC network.. Good Luck! Tim Syratt On Mon, 17 Nov 2003, J. Bilder wrote:
Irc isn't the easiest to close. If they are looking to block IRC, then they better block all the ports so that people cant BNC to other hosts. Depending upon how the network is setup, you can BNC on any port to get outside. Unless of course the company has a firewall that only allows proxy sessions from a few hosts, and all other ports are locked down to servers as well. Then it would be especially hard to get outside. They would probably also be looking for someone scanning the firewall to see where they could potentially find an open port to get out on as well. HTH - Jeff On Mon, 2003-11-17 at 14:46, Mike wrote:Hi All, I'm looking at moving my career towards security, so was interested when I received an email from our security department that stated they would be blocking IRC by closing ports 6665-6669. I would have thought a lot more ports would need to be closed if the secops wanted to completely block IRC. What is the "best" way to disable access to IRC? Block known ports, what ports would need to be blocked? Or just drop packets, how would that be done? We use Cisco equipment and are primarily a win2k 70% winxp 30% site Like I said I'm wanting to move into security, but at the moment I wouldn't even class myself as a novice. Any input I could get from this list will be very much appreciated! Thanks Mike --------------------------------------------------------------------------- Forum Systems PRESIDIO: PGP / XML GATEWAY APPLIANCE The Presidio integrates PGP data encryption and XML Web Services security to simplify the management and deployment of PGP and reduce overall PGP costs by up to 80%. FREE WHITEPAPER & 30 Day Trial - http://www.securityfocus.com/sponsor/ForumSystems_security-basics_031027 ------------------------------------------------------------------------------------------------------------------------------------------------------- Forum Systems PRESIDIO: PGP / XML GATEWAY APPLIANCE The Presidio integrates PGP data encryption and XML Web Services security to simplify the management and deployment of PGP and reduce overall PGP costs by up to 80%. FREE WHITEPAPER & 30 Day Trial - http://www.securityfocus.com/sponsor/ForumSystems_security-basics_031027 ----------------------------------------------------------------------------
--------------------------------------------------------------------------- Forum Systems PRESIDIO: PGP / XML GATEWAY APPLIANCE The Presidio integrates PGP data encryption and XML Web Services security to simplify the management and deployment of PGP and reduce overall PGP costs by up to 80%. FREE WHITEPAPER & 30 Day Trial - http://www.securityfocus.com/sponsor/ForumSystems_security-basics_031027 ----------------------------------------------------------------------------
Current thread:
- Blocking IRC Access Mike (Nov 17)
- Re: Blocking IRC Access J. Bilder (Nov 17)
- Re: Blocking IRC Access Andreas Haugsnes (Nov 17)
- Re: Blocking IRC Access Tim Syratt (Nov 18)
- RE: Blocking IRC Access JM (Nov 18)
- <Possible follow-ups>
- SV: Blocking IRC Access Thomas Westlund (Nov 17)
- Re: Blocking IRC Access getting_out (Nov 19)
- Re: Blocking IRC Access J. Bilder (Nov 17)