Comcast Gateway + Netgear Router ports

[Narh]

Long story short:
I had forwarded ports on my router a few years ago and all was fine an dandy until just recently. Comcast replaced my modem with a "Gateway Device" and now all my open ports are not being detected (Simple Port tester and shields up failed to reach/listen to them).
I am able to log into the gateway the same way I would a router, and I noticed that 1) port forwarding on the gateway itself was Disabled, and 2) There is no "add exception to firewall" Just Maximum, Partial, and Minimum settings.

Would either of those have something to do with my problem?
Dont want to go clicking buttons just yet.. Thats how I bricked my last one xD

Router: Netgear WNR2000v3
Gateway: Xfinity Technicolor TC8305C

 

[reflex99]

OOOOOH I got this if you haven't already figured it out.

Basically, the Gateway they gave you is a Gateway/Modem/Router/WifiAP(on some models) all in one. This means not only does it access the WAN through the cable, but it also acts as a DHCP server, port forwarder, and creates a Wifi network.

Well, all of these parts suck, and you probably only want the Modem/Gateway part (Ill just say modem from here on), and then use the Netgear for routing/port forwarding/etc. The WebGUI on the ARRIS unit sucks especially hard.

Since comcast is a bag of dicks, you can't disable the router/AP by yourself. To do that you need to contact support.

There are three "modes" that your modem can be in:

-Normal: This is the default, all the functions enabled, so Modem, NAT, Router, WiFi, all there.

-Bridge mode: this is closer to what you want. Wifi is disabled, but the Comcast device will still do Routing and Modem things.

-FULL bridge mode: This is what you want. This turns the device into a modem only device. It will disable the Wifi functions as well as routing. Obviously you'll need a router, but luckily your netgear can do that.

So when you contact support, you need to ask them to put your modem in "FULL BRIDGE MODE". There's a 50% chance they won't know what you're talking about, so you'll have to try again and hope for a different agent who does know. It may help if you explain that you want to use your own ROUTER and WIFI ACCESS POINT. AKA you do not need any of the functions on the comcast device other than the MODEM.

This is a pretty technical thing, so i'd imagine few people request this, and therefore the reps might not know what you're talking about. The first time I contacted them, they put it in bridge mode, but not FULL. I was getting routing errors since my personal router and the comcast unit were both acting as DHCP servers. Contacted them again, and after a bit of runaround, then got it into full bridge mode. After they do this, the comcast device will act like an old-school modem, only connecting your cable to the WAN, and outputing a single WAN ethernet port that you should plug into your router. You can confirm that you are in FULL BRIDGE MODE by seeing if you can access the modem's webgui. If you can, you're not in full bridge, if you can't, then you're golden.

For what its worth, I used their online support chat. Some people report better results with phone support, but I had very few issues with web chat.

After you do this you can port forward and whatnot through the Netgear interface and use the Netgear for portforwarding duties, and everything else.

hopefully that makes sense, I'm a poor writer.

 

[Narh]

Comcast, True to their reputation, Refused to help me. Only they can change it to Bridge mode. Even the field tech they put on the line seemed to tell me "they know whats best", and offered to give me a static IP to use for the low low price of $15 a month... yea...
I ended up setting the Gateway as a DMZ host and to my router.

Not what I would prefer, but it works =\

 

[CrossCheck]

Why don't you go buy your own modem like the Motorola surfboard. Especially if you are not using their phone service. You don't have to use theirs