OK, so, I'm sort of the de facto IT guy for my office and I've run into an issue with hooking up a D-Link DIR-655 to the Comcast Business gateway (model SMCD3G-CCR). I've done networking stuff in the past, but this is maybe a little over my head. We want to use the D-Link for wireless since the Comcast gateway doesn't have it. Comcast told me that it would be as simple as hooking the router up to the existing gateway and there'd be no issue...well, then reality reared its ugly head and killed that notion.
Here's a rough version of how we're set up: The Comcast gateway has 4 ports, and I think is acting as a router and a modem. Currently, 3 of the ports from that gateway go to what I think is an unpowered switch (it's a board with 12 ethernet ports on the front...here's a picture:
The other port goes directly to another PC.
We also have 4 IP phones downstream of everything, but I don't think they'd affect the situation.
What I have tried so far is that I took one of the ports from the gateway and connected it to port 1 on the D-Link, then hooked another cable to port 2 and then hooked it into the switch, more or less adding the D-Link to the loop. The good news is that everything appeared to work fine, we were able to see the wireless signal, access the internet through it, and the wired computer that was routed through the D-Link was working correctly.
Then the problems started...
First off, I'm not able to access the router to enable a wireless key. The router is assigning IPs in the range of 10.1.10.xxx, and the Comcast admin panel shows me everything connected, and the router doesn't show up. I even tried just manually putting in IPs in that range to see if I could find it, but I had no luck.
Secondly, after a while, connections started to go down. One of the computers, not the one hooked into the D-Link, lost connectivity completely and the IP phone in that office displayed "Searching for DNS". I was only able to fix this by completely removing the D-Link from the network entirely, leaving us without wireless.
OK, I hope that makes some sense, and I hope someone can help me. Thanks in advance!