DOCSIS 3.0 Bridging?

chpalmer · Sep 12, 2012, 1:03 AM

Comcast or other??

dchicks · Sep 12, 2012, 5:33 AM

Comcast cable. I am using a Zoom Docsis 3.0 Modem/Router combo on it right now. It's not clear at all how to turn off all of the router/firewall goop on the device. Then, of course, I'm not sure how to configure it in pfSense. I assume it's not static, but not exactly DHCP, either?

Thanks for the replies!
Dave

cmb · Sep 12, 2012, 6:58 AM

With Comcast business you're assigned at least a /30 subnet if not a /29 on the inside of the modem, which is what you use on the firewall's WAN.

dchicks · Sep 12, 2012, 3:40 PM

No, this is residential Comcast. :) I did try to get business class, but it was not available. I finally found the CD that came with the modem. Hopefully, the manual on it will have some answers about bridging the modem. The rest, I may have to contact Comcast to find out, if they will even tell me.

matguy · Sep 12, 2012, 7:05 PM

Can you tell us what model of Zoom cable modem you have. I have a Docsis 3 Zoom Cable Modem, and it doesn't do NAT by default.

johnpoz · Sep 12, 2012, 7:29 PM

If its called a cable "modem" it wouldn't be doing nat - they do have "gateway" cable devices that would. But normally a cable modem does not do any nat. As already requested what is the model number of the zoom device you have?

dchicks · Sep 12, 2012, 7:39 PM

It is the Zoom 5350 Cable Modem/Router. It does do NAT by default. There is an option to disable the firewall and DHCP server, but I haven't found any options to disable NAT. I've sent a question to Zoom to ask about it. My suspicion is that I'm going to have to get a new modem-only device that will pass the public IP on to pfSense for me. The user's manual on the CD was absolutely no help either. It was basically a tour of the menus.

johnpoz · Sep 12, 2012, 7:52 PM

What does this do? ;)

dchicks · Sep 12, 2012, 7:54 PM

Bah! I must be blind. Somehow, I completely missed that option. I'll give it a try when I get back to the house.
Thanks!

dchicks · Sep 13, 2012, 2:16 AM

I tried disabling NAT. That simply made things unusable. Had to reset the device to get it working again.

In the meantime, I received a reply from Zoom. Without admitting that the modem/router can't be configured as a bridge, I was advised to purchase just a "modem" that would act in bridge mode. So, I did that. I picked up a Cisco DPC3008. After a bit of fiddling and a couple of calls to Comcast, I've got it working with my NetGate pfSense router.

Thanks for all the input. I'm sure you'll be hearing more from me as I try to figure out how to configure the firewall, port forwarding and failover stuff. I'll try not to be a pest, though.

Cheers,
Dave