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Networking issue with Netgear CG814CCR (SonicWall, Vonage)

Last Modified: 2008-04-24
I have a field office with Comcast service. The device is the Netgear CG814CCR. We have a static IP defined to this device. We are using vonage for our phone service. The problem is that the device tends to cause problems if we use any other routing device behind it. Our goal is to hook up a SonicWall TZ-170W behind the device and establish a VPN tunnel to our main office's PRO2040 device. The tunnel establishes fine and works for awhile, then the two networks quit talking to each other (pings fail). We thought we may have a SonicWall issue, but removed the device from the topography totally (using the built in router on the Vonage). We then connected a PC using the SonicWall Global VPN client and the same connectivity issues reappeared. The only way we can get any stability at all is to connect our PC's/phones directly into the CG814CCR. We still have some voice issues occasionally, but it is much more stable. Since the symptoms occur without the firewall in place, I'm confident that isn't the issue. Comcast says they can't see any problems, and have been mostly unresponsive in helping diagnose the problem. Presently, we have our PC's/printers plugged directly into the CG814CCR, getting IP addresses from the device. We have another field office using a TZ170 using a tunnel and it works perfectly. I reallly thinik the problem is within the CG814CCR device, but am having difficulty getting anybody at Comcast to believe me. They swear that the built in firewall is turned off, but I have my doubts. Ideally, we only need that device for the Static IP and we can handle everything else with our SonicWall. Am i missing something here or am I right in pursuing this with Comcast? I'm really at a loss into how to proceed. This isn't a complicated setup at all. Any advice or suggestions would be appreciated.
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Comcast support is horrible, and the only way to prove anything to them is via extensive ping tests, using every scenario.  What router is needed for the Vonage service, is that the CG814CCR?  I can't find much info on that device, is it the actual cable modem?  If not, just take it out the picture all together and assign the static to your sonicwall.  If it is, then you can always replace it with a regular cable modem, with no routing capabilities, and assign the static to your sonicwall.


The CG814CCR is the actual cable modem/router sent to us by Comcast. Their support tells me that other cable modems won't with their network (sigh). Not sure if I believe that either. The Vonage device is a Motorola VT2442 (with router capablities). Another issue compounding the problem is that I am 3 hours away from the sight. I'm dangerously close to giving up the bandwith and getting Verizon DSL. I've had better luck with their support, but as I said, this setup isn't that complicated.
Yea, I wouldn't pay much attention to comcast's first level of support.  I have comcast and know i can replace it with another cable modem.  You would just have to get them the new mac address.  If you decide to try a new cable modem, make sure its compatible with Vonage.  You will need one with DOCSIS version 1.1 or 2.0, but I'm sure any new one you buy will be at one of those versions already.


tduplants: Check out this thread if you have time. I know it's pretty long, but this sounds alot like the issue I'm having.
This one is on us!
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Thanks for your advice; I will pursue that solution. Ironically enough, the area where this field office is located is in an area where Comcast recently bought out Adelphia.


Comcast finally agreed that there was an issue with how the Netgear router communicated with the SonicWall. Level 2 technical support recommended a different business class router/modem (SMC). When this modem was installed, we suffered the same (actually worse) symptoms. I purchased a Motorola cable modem, one without any routing capabilities and called Comcast. They initially declined my request to add the MAC id to my account, stating that the modem was not supported and that our account would not be supported if I installed it. Given no other options at that point, I convinced them to add the modem. Miraculously, after configuring the SonicWall to use dynamic instead of static IP's, everything resolved itself. The issue all along was with the equipment sent by Comcast. Once I installed a cable modem with no routing capabilities, all was well in the VPN world. Comcast technical support is terrible (level one is anyway). I'm sure there was someone in their support department who could have corrected what i was gong thru, but they are difficult to connect with when all the level one support wants to do is tell you that because the internet is working, the problem must be on the customer end. In a nutshell, I should have gotten my own modem from the start and trusted my instincts. Thanks to all on the board for the help.  

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