I'm having problems with Remote Desktop ... the Linksys router is correctly configured to forward Port 3389 to the static IP of the target computer. The router's Internet connection is setup using the static WAN IP address assigned by Comcast. I can ping the WAN IP address one-up from the address in the Router's static IP address (.10) but not the IP address in the Router's firmware (.9). The Comcast firmware is accessed using the 10.0 range; the Linksys router is accessed using the 198.162 range.
The internet works fine, but I am unable to use RDP. Is there anything that needs to be setup inside the Comcast Gateway to enable RDP?
That should work, although pinging the router's WAN IP address may fail depending on how the router is configured. Let's see your specific 3389 forwarding entry in the router. Also check the firewall on the target computer to make srue it is allowing incoming connections for RDP, as well as the RDP setup itself.
Is this a Comcast Business account? Exactly what gateway are you using?
When you say "How the router is configured," I'm not sure if you mean the Linksys (which adds wireless) or the Comcast (it's an SMC Gateway, which appears to be a router as well as a modem). I'm 100% confident about the port forwarding, firewall exception and RDP setup ... I think the issue must have something to with a conflict between the Linksys router and the Comcast ... the Linksys is the DHCP, and hands out addresses in the 192. range ... the SMC/Comcast Device is in the 10. range.
It is a Comcast Business account, with the Comcast-supplied SMC Gateway.
OK, so you have two routers connected in series? That's your problem, you need the port forwarding setup in BOTH places, in the SMC gateway to the Linksys WAN IP and in the Linksys to the target system. I have no idea what kind of problems you will introduce with a double NAT traversal on your RDP connection.
That's not a good setup for many reason. I've no knowledge of the Business account side of things, but why are you running a gateway AND a router? If you were just adding wireless capability because the gateway did not have it, you should have gotten a WAP, not a wireless router. Many wireless routers can be dumbed down to a WAP, but it takes some know-how and there can still be problems, not to mention it really complicates things.
Another option is if the gateway is not contractually required is to replace it with a standalone cable modem and move the public static IP setup into the Linksys. This really simplifies your setup, unless you have other considerations.
Why it was setup that way I'm not sure ... the previous ISP was RoadRunner; Comcast came in and replaced the RoadRunnder modem with the SMC Comcast Gateway and connected as described. But it seems you're suggesting a solution? Within the SMC router, Port forward 3389 to the WAN IP specified in the Linksys Router? The Linksys is already forwarded to the target PC, so nothing would need to be done there.
OK, it sound like Comcast replaced a modem only with w router/modem gateway device, which, as Baric describes, gives you two routing devices in series...If you are not using wireless, and you can configure port forwarding on the Comcast gateway, the most efficient solution would be to remove the internal router from the network, and just use the Comcast gateway. You may have to reconfigure your network a bit, if you have static IPs on some of your devices.
There are more complicated options, that would involve the use of both routers....
It would work buy as pointed out, the results may be unpredictable for RDP connections, and it is unnecessarily complex. You could connect the gateway to one of the LAN ports of the Linksys, instead of the WAN port, medically using it just as a switch. This would bypass the hardware firewall in the Links ys
I'm not a fan of configuring the wireless router as a WAP, but it can be done. You also have the additional complication of two DCHP server, one in the gateway and one in the wireless router, both on different subnets. I'd replace the Linksys router with a WAP and configure the WAP on the same subnet as the gateway, with the wireless IP range with on overlap with the DHCP server in the gateway. Or turn off the WAP DHCP server and let the gateway handle it.
If you decide to go with the existing wireless router, if you give us the exact model and configuration we can probably provide a list with the basic steps you will need to make it a WAP.