Comcast Modem IP Change

apparently, I can't change my ip with normal means. I have a comcast modem and I'm trying to change its ip address.

using ip release didn't work, nor did unplugging my modem over night. I also did some stuff in the ctrl panel.

Well anyway, does anyone know how i can change my ip on my comcast modem? calling is an option but I want to do it often. Reason is because I have an automated program that requires proxies, and also I messed up with using seoQuake

thanks

 

If your ISP assigned you a "Static" IP address then I'm pretty sure you normally can't change it without contacting them about it.

 

If your router lets you clone or spoof the MAC address, try changing the MAC address of the WAN interface. Then reset the cable modem.

If your router doesn't support changing/cloning MAC addys, you can hook up your laptop directly to the cable modem and reset the modem. If you then swap it back to the router there is a chance it will pull a new IP as long as you let some time pass.

This assumes you aren't on a static IP like a business class pipe, etc.

You should probably read the user documentation for the apps or browser plugins that are giving you problems necessitating a new IP. Generally these are terms of service violations - you can get your whole subnet banned if you just keep doing what you're doing - not a good idea.

 

Well if you have a static then there is no reason to change your IP. If your leased an IP you could try wiping the router back to defaults and setting it up from scratch. As for unplugging the router overnight it will retain the IP info in NVram. Not sure how long IP leases are from comcast in your area, but Im pretty sure they wont lease your IP address out from under you over night and give you a new one as thats much unneeded network overhead.

 

Wiping the router will do no good, you can just do a dhcp release on the router's WAN interface if that was going to solve it.

The problem is that the DHCP server will have the IP tied to the MAC address for however long the lease lasts. If you change the MAC address either by spoofing/cloning or by using a different ethernet interface (like a laptop) the new dhcp request should pull a new IP and the other lease should be flushed after some time.

 

Good point.

 

Meh I could be completely wrong though. I haven't tried it myself to know for sure.

Comcast has some funky network management that's for certain. It's not high on my list of good things (TM).

 

If your Comcast modem has a MAC address and your "Static" IP is based on the device and not your (router/laptop/computer) then spoofing/cloning your MAC address on your (router/laptop/computer) will not change your IP address. I've already tried this method with Time Warner.

If you can spoof the MAC address on the Comcast modem itself then you will most likely have no Internet connection. I'm not exactly sure though, I never tried it for more than a day. I did try releasing the IP address, resetting the modem, etc.

This is just from my experience; it could be different in your situation.

 

You may have to leave the modem turned off and disconnected for several days before the ISP will release the IP address back to its pool of IP addresses, at which point a new one will be assigned to your connection.

I say this because it's customary for a lot of people to turn their cable modems off at night, so I would think that, in general, the Comcast equipment is set up to not release an IP address from an account until the account has been turned off for at least a few days.