Network Configuration with Comcast Business Class modem
Posted on 2012-03-26
I recently installed Comcast Business Class service, and the tech installed an SMCD3G modem, which includes 4 LAN ports.
I also have a Cisco RVS4000 router/firewall which I'm using as my main router. I also have a wireless access point, but at the moment I'm not concerned with that.
The basic setup works fine, and I'm able to use the internet, get email, etc etc. However, I have a hosted remote access utility (ScreenConnect) which I use to provide remote support to my clients, and after the Comcast install I need to re-configure for this. Note that previously, with my Motorola Modem + RVS4000 everything worked well.
I cannot get external internet traffic routed to my Screenconnect utility. The configuration is like this:
All internal network resources, including the machine hosting ScreenConnect utility
The Comcast modem is set to use the standard 10.1.10.xx IP ranges, but the RVS4000 is using the 192.168.1.xx ranges. If I change the RVS to use a 10.1.10.xx address, I can't get the boxes to talk to each other, and I cannot do anything internet-related.
I've exhausted my knowledge of network setup, and would like to ask for your assitance in the best way to configure this. I'd much prefer that all my internal network resources flow from the RVS4000, since I have much greater faith in the firewall there than I do in the Comcast modem. I'm not sure if I need to somehow "bridge" the Comcast modem with the RVS box.
How can I configure the two components so that they can co-exist on the same network, and so that I can forward traffic to my ScreenConnect utility?
I've set the Comcast modem as the DHCP server, and disabled the firewall on that device (the firewall on the RVS is active). I've disabled the DHCP server on the RVS box. On that box, the appropriate ports are forwarded for the ScreenConnect traffic (and remember this worked well before the install of the Comcast modem).
Note too that if I connect directly using my current WAN address, I see the Comcast Modem sign in screen, so I'm confident that I can reach that (and I've done this from a remote network as well). However, if I enter my ScreenConnect port (i.e. 18.104.22.168:8040) then I get the "interent explorer cannot display the page" error.