Comcast IP Problems

[myron]

Hi -

I am running through a Linksys BEFw11S4 v.2 router, and use Azureus as my torrent program. I had my port forwarding all set up with no problems, and was not receiving NAT errors.

In the last month, Comcast sent out letters through email and snail mail stating that they were making changes to their service, and that any users who had their systems set up to use a static ip address had to change to a dynamic ip address or they would not be able to connect to the internet anymore. I made the change as they recomended, but this has made it seemingly impossible to get my ports forwarded correctly.

All was fine before, but all directions I can find make it clear that you must be set up with a static ip address to forward ports. Comcast forced me to switch to dynamic. Now I receive NAT errors no matter what I do.

Can anyone help me out? I am suprised that nobody else has mentioned this, there must be many others out there with the same problem.

Brett :(

[showtaper]

I'd like to know as well, I'm on Comcast and their tech support people are
pretty much worthless......

[jazzbo]

All was fine before, but all directions I can find make it clear that you must be set up with a static ip address to forward ports. Comcast forced me to switch to dynamic. Now I receive NAT errors no matter what I do.


Okay, there are two different sets of IPs -- one is a WAN and one is LAN. The IP assigned by your ISP (Comcast) to your connection is the WAN and the IP you assign to the machines behind your modem/router is the LAN. These should be in a protected range and will start with one of the following:

10.x.x.x
172.16-31.x.x
192.168.x.x

It is this second set of LAN IPs which most port forwarding instructions say should be static in order for port forwarding to work correctly.

Theoretically every time your router renews it lease through the modem it could be given a new WAN IP, but that shouldn't matter as it will still forward connections on the selected port back to the staticly assigned LAN IP on your local network. If you have access to the router, you have the ability to determine if your computer gets a static or dynamic IP on the LAN.

[irishcrazy2005]

I have a question related to this. I have a Linksys router, which I have access to, and I am having a problem where every couple of weeks or so my local LAN IP changes. It is always XXX.XXX.X.101 - XXX.XXX.X.103, but this is annoying because every so often I need to go in and change the port forwarding to send my bit torrent ports to my computer. Any ideas on why this is happening or how to correct it would be appreciated. Thanks.

P.S. It is probably useful to know that I am the only computer on this network

[jazzbo]

I have a question related to this. I have a Linksys router, which I have access to, and I am having a problem where every couple of weeks or so my local LAN IP changes. It is always XXX.XXX.X.101 - XXX.XXX.X.103, but this is annoying because every so often I need to go in and change the port forwarding to send my bit torrent ports to my computer. Any ideas on why this is happening or how to correct it would be appreciated.

You probably have your router set to assign dynamic LAN IPs and to start with a range over 100 and the operating system on your PC is set to automatically acquire an IP from the router.

This link on the portforward site should help you set your PC to a static IP -- you may want to pick a lower number for the last part of the IP so it won't interfere if you later put other devices on your network.

http://www.portforward.com/networking/staticip.htm

[Drewa311]

I was told by 2 different comcaste dudes that i could have a static IP. I spent a alot of time on the phone with them bitching and whatnot. Anyhow, i got an american, he aksed me what i needed my ports forwarded for, and i said for stuff on oink, he warmed up and told me a bunch of stuff he shouldnt have. He told me that comcast rents their ips, and that a specific ip for a houshold will only change if the ip expires. He said on his comp, he also used for torrents on comcast service, the ip didnt change for 9 months, then one day his ports wernt forwarded anymore, he just had to reforward them. This didnt help me having my ports forwarded. What worked for me, and this sounds weird im sure, I just plugged into my pc directly from the comcast box, and then back through the router and i guess it recognized the ip and i ports are forwarded, not here, but im clever oink. thats what i know about comcast