Adapter before the Router/Comcast Warning Letter

Posts: 64

Have only been a Vonage customer for a month. After having serious problems with clicking and cutting out, we moved the adapter before the router and everything worked fantastic. This setup is shown by Vonage.

Today, we received a letter from Comcast stating that their records indicate we are using more than one dynamic IP address and stated that on May 11th, the additional IP would be removed if they did not hear from us. Two options to keep things the way they are were paying for an additional IP address (cost ?) or purchasing "Comcast Home Networking" (outrageously priced). Two hours after receiving the letter, Comcast must've axed the IP address because we couldn't make or receive phone calls, so we moved the adapter after the router and are back to clicking and cutting out.

Coincidentally, we are trying to port our phone number from Comcast Digital Phone, and it's past the minimum 20 days, so am paying for yet another month of service until that happens. I'm wondering if the request prompted checking, which prompted the letter.

Is this fair? Has anyone else had trouble with Comcast or their cable internet company? I think Vonage needs to put a warning on the Installation with Multiple Computers instructions for Comcast customers. At least for us, there is a HUGE difference between having the adapter installed after the router, which makes Vonage practically unusable.

Posts: 38 · Posted: Fri Apr 30, 2004 6:48 am Post subject:

If it were me, I would run Spybot S&D, AdAware, and RegVac on your system. Then go to http://housecall.trendmicro.com and run an online virus scan. It sounds like you may have a lot of junk on your systems that is eating up valuable bandwidth. Placing the ATA before the router enables the QoS feature on the ATA to work, but you shouldn't need it if you have enough bandwidth. Give that a try and let us know how it works.

Posts: 89 · Vonage Forum Senior Joined: Feb 04, 2004 Posts: 89

I have been using my Motorola ATA (in pass-through mode) in front of my router for 3 months and I also use Comcast. I have not received any letters from them, yet. QoS was working and Vonage's call quality has been excellent with one exception. One day I was emailing some jpeg pictures and the upload was taking most of the bandwidth. QoS did not help at all there. Unfortunately that happend during a business call. Yesterday I moved the ATA behind my Linksys WRT54G router and flashed the router with Sveasoft firmware. The firmware added like 20 new features to the router, one of them bandwidth management. So now the ATA always gets the same IP address from my router i.e. 192.168.1.100 and my computers get addresses starting at 101. I am doing bandwidth management on all IP addresses that are 101 or higher, leaving the ATA traffic untouched. Its been only one day, but so far so good. Today I plan to upload a bunch of pictures to the Internet and will make some phone calls at the same time.

Posts: 64 · Posted: Fri Apr 30, 2004 11:58 am Post subject:

Thank you everyone for the replies, I run Trend's antivirus software in real scan continually, and also run SpyBot. I also have the free version of AdAware that I'll run about every 2 weeks just to pick up stuff that SpyBot doesn't. I'll get RegVac now.

I am concerned about the spoofing of an IP address, is there any way to check this? What would do that?

I called Comcast and their tech group said they weren't given any reasons for why people got that letter except that they were people using more than one IP, and if a person had a router, then they wouldn't have a problem. The ATA was the only piece of equipment we've ever used in front of the router before so it's why I suspected it. They said they were told it was mostly a problem with people running hubs instead of routers (we're not). Said that nothing would be cut off until May 11th, so maybe it was a coincidence that the phone quit working? Funny that it immediately worked after it was moved though.

Maybe we need a new router? Have a Linysys BEFSR41. Maybe there are updates to it, so I'll try to figure that out.

Thanks again.

Posts: 64 · Posted: Fri Apr 30, 2004 1:54 pm Post subject:

Update.. Ran RegVac, Spybot, Trend, AdAware - nothing suspicious. Also updated the firmware in the router so have version 1.45.7, which is the most recent.

If anyone has an idea on what I could check to see if our IP address is being spoofed, I'd greatly appreciate it.

I'd sure like to move the ATA back in front of the router. I still have the feeling that is what prompted the letter from Comcast.

Posts: 64 · Posted: Fri Apr 30, 2004 2:09 pm Post subject:

Sorry for rambling on here, but I just found a post that said this:

If you can get two IP addresses from your modem (I can't without paying for it) you might be able to use "pass through mode". The trick is to turn off the MTA's NAT server in configuation. It then acts as a bridge and your router will get an IP from your ISP and the MTA will get another IP from your ISP. This only works if your ISP will issue you two IPs without disconnecting the other one.

The other way to do this would be to hook a switch to your modem and hook the MTA to one port and the router to the other port. But again, your ISP has to let you lease two IPs.

Is it possible that is what happened with us? Maybe Comcast was allowing it and now they're running software to detect the people who are using more than one IP address?

Posts: 2 · New Forum Member Joined: May 01, 2004 Posts: 2

PaulaBerge wrote:

Sorry for rambling on here, but I just found a post that said this:

If you can get two IP addresses from your modem (I can't without paying for it) you might be able to use "pass through mode". The trick is to turn off the MTA's NAT server in configuation. It then acts as a bridge and your router will get an IP from your ISP and the MTA will get another IP from your ISP. This only works if your ISP will issue you two IPs without disconnecting the other one.

The other way to do this would be to hook a switch to your modem and hook the MTA to one port and the router to the other port. But again, your ISP has to let you lease two IPs.

Is it possible that is what happened with us? Maybe Comcast was allowing it and now they're running software to detect the people who are using more than one IP address?

I have Comcast and my setup is the same as described here. It's working great, but I was kind of surprised that Comcast is letting me get two IP addresses. I guess it's just a matter of time before I get my own letter from Comcast . . .

Posts: 64 · Posted: Sat May 01, 2004 8:21 pm Post subject:

Quote:

I have Comcast and my setup is the same as described here. It's working great, but I was kind of surprised that Comcast is letting me get two IP addresses. I guess it's just a matter of time before I get my own letter from Comcast . . .

I hope you don't. I'm in a suburb of St. Paul/Minneapolis so hopefully we're just a test area with some software they acquired.

How can you tell if you are getting two IP addresses? When I was on the phone with Vongage CS yesterday, they said it was impossible if the ATA was after the cable modem and before the router. I have no idea if we were using pass-through mode or not, all we did was put the ATA before the router and it worked great. I have no idea how to change setttings on the ATA anyway.

Posts: 2 · New Forum Member Joined: May 01, 2004 Posts: 2

PaulaBerge wrote:

Quote:

I have Comcast and my setup is the same as described here. It's working great, but I was kind of surprised that Comcast is letting me get two IP addresses. I guess it's just a matter of time before I get my own letter from Comcast . . .

I hope you don't. I'm in a suburb of St. Paul/Minneapolis so hopefully we're just a test area with some software they acquired.

How can you tell if you are getting two IP addresses? When I was on the phone with Vongage CS yesterday, they said it was impossible if the ATA was after the cable modem and before the router. I have no idea if we were using pass-through mode or not, all we did was put the ATA before the router and it worked great. I have no idea how to change setttings on the ATA anyway.

I connected to the ATA using this URL http://192.168.102.1. By default, the ATA is set to do NAT and I disabled that feature. By disabling NAT on the ATA, my router which is connected behind the ATA can still do DHCP and get an IP address from Comcast. I confirmed that both my router and the ATA were each getting an IP address from Comcast by looking at the configuration pages for each. This setup was necessary for me because my Checkpoint VPN client for work would not work with NAT enabled on the ATA and router. This configuration allows me to use my VPN client and still have the voice QOS features of the ATA. It's working great!

Posts: 66 · Full Forum Member Joined: Dec 15, 2003 Posts: 66

Paula, if Comcast won't allow 2 IP addresses and you want the Moto between the cable modem and your router or PC, you have to put the Moto into NAT mode. That way, the Moto is the only device to get an IP address from the ISP.

You may find as did another poster in this thread that some VPN or another app may not work, but most people wil be happy.

My cable Internet provider is RoadRunner in Minneapolis. They explicitly allow 2 IP addresses, so I operate the Moto in bridge mode so that the Moto doesn't interfere with any data applications. But I have also operated in NAT and everything seems to work fine.

Bob