Security Basics mailing list archives
RE: Cable Modems Need Open Ports?
From: "Mike Marcus" <mmarcus () nelsonpub com>
Date: Mon, 4 Nov 2002 16:20:20 -0500
To All, Thanks again for all your replies. It appears that since my new DOCSIS modem any changes filter changes I make to the netgear router will cause the problem. If I power down the modem and router, power up the modem and then the router everything is just fine. This symptom did not show up with my older cable modem (pre-DOCSIS). So this appears to be a sync problem between the router and the modem. Once they are up, all is fine. I will be getting another router with more firewall features and will try it with the new modem. Thanks again to all who participate. The information is helpful. Mike -----Original Message----- From: Raoul Armfield [mailto:armfield () amnh org] Sent: Monday, November 04, 2002 3:27 PM To: Case CCC; Mike Marcus Cc: security-basics () securityfocus com Subject: RE: Cable Modems Need Open Ports? I have a linksys router with a cable modem and have block everything incoming and have no problems resolving dns names. It seems to me that it shouldn't need to connect through port 53 since you are making the requests. Isn't port 53 listening for inbound requests? :-----Original Message----- :From: Case CCC [mailto:case_list () operamail com] :Sent: Saturday, November 02, 2002 12:46 AM :To: Mike Marcus :Subject: Re: Cable Modems Need Open Ports? : : :I believe port 53 is required to resolve the namespaces, :like yahho.com to 64.58.79.x... Also, port 59 is used :by new file to talk back and forth to the server that :keeps the token lists. : :I would recommend doing a google search with : :'TCP/IP Ports 53 59' : :Try blocking one or the other see what happens, :trial and error is a harsh mistress but a great :teacher. : :external IP i assume you mean the WAN side on you :router/modem NIC. : :case :console_cowboy : : : : : : :> I was "playing" with setting on my router that is connected to a :cable modem :> (Comcast is the ISP). After blocking incoming (from wan) UDP :and TCP ports :> 53 and 59 the router lost its external IP. Any ideas? :> :> Thanks, :> :> Mike : : : :-- :_______________________________________________ :Get your free email from http://mymail.operamail.com : :Powered by Outblaze :
Current thread:
- Cable Modems Need Open Ports? Mike Marcus (Nov 01)
- RE: Cable Modems Need Open Ports? Dallas Hindle (Nov 04)
- Re: Cable Modems Need Open Ports? Lance Reck (Nov 04)
- <Possible follow-ups>
- Re: Cable Modems Need Open Ports? Case CCC (Nov 04)
- RE: Cable Modems Need Open Ports? Raoul Armfield (Nov 08)
- RE: Cable Modems Need Open Ports? Mike Marcus (Nov 08)
- RE: Cable Modems Need Open Ports? Raoul Armfield (Nov 08)