Would I need to do something similar to what is described in the article for the Windows Server at my workplace?
Yes, but the details all depend on what firewall is between the server and your remote access system. If the server is just sitting behind the Comcast SMC gateway, and no other router or firewall in between, then just log into the gateway and port forward 3389 as instructed to the IP address of the server. Then on the server, make sure the firewall there is accepting external connections and that Remote Desktop is configured with the proper users and allowing connections.
Bear in mind that those port forwarding instructions are generic. Your Comcast gateway is likely sitting at 10.1.0.1, not 192.168.1.1 or 192.168.0.1. And the actual steps once into the device vary quite a bit. Consult your specific model's manual for details.
What is the IP address of the SMC gateway, 192.168.102.1? Or is that the IP address of some other router sitting behind the SMC? If so, you have a double NAT setup (ie two NAT routers connected in series), and must port forward on the first to the WAN interface IP of the 2nd, then port forward on the 2nd router to the actual server IP address.
Um, why two IP addresses on the same machine to the same subnet? Not that you can't do that, but it requires some work setup and properly maintain a multi-homed machine.
Your computer is connected to another router sitting at 192.168.102.1, that is where the default gateway is and that is where all incoming connections have to go through. So, you have to log into this router (whatever it is), find it's WAN IP address and setup port forwarding on the SMC to this new router's WAN IP address, then another port forwarding setup in this new router pointing to your computer's IP address. So your setup looks something like this (baring any other unknow routers):
Internet --> (public IP) SMC gateway (10.1.10.1) --> (10.1.10.x) mysterious router (192.168.102.1) --> (192.168.102.12) your computer
For an incoming RDP connection on port 3389, the request has to hit the SMC gateway, find a port forward there to be directed to the unknown router's , find another port forward there which in turn directs it on finally to your computer.
Double NAT setups are ... messy. They can be made to work, but they require extra care and feeding, and will slow things down a bit, depending on the router throughputs and configurations.
That makes perfect sense... But I'm having problems getting into the second router. It's a Netgear RT311. When I enter the 192.168.102.1 IP address in the browser address bar, I get an "Internet Explorer cannot display the webpage" error message. Any ideas on why that would be happening?
Some older versions of IE required that if your URL is an IP address, you had to manually enter the "http://" explicitly. If that doesn't work, try Firefox.
That router is OLD (and probably MOLDY, too). It even has an old style RS-232 serial port for "advanced" configuration, or via telnet, not all functions are available through the web interface. To use the serial port, you will need a serial cable and a terminal program to get that level of access. See your manual, Ch 4 and 5 about how to use the web interface or the more "advanced" Manager interface via serial port or telnet.
If it were me, I would get rid of it now, replace it either with a plain ethernet switch (and let the SMC handle the routing duties and only one port forwarding setup required), or a more modern router with better capabilites, like gigabit ethernet ports, a full web admin interface, better throughput, etc.
If you do go with an ethernet switch, make sure you understand what's connected through the router and how the change would effect the IP addresses and routing setups of those systems currently using the RT311.
I'm actually offsite from the office - but I believe the person I'm working with onsite did type in http://192.168.102.1 in the browser address bar (I'll double check that with him).
It sounds like it would be a good idea to get rid of the Netgear router... I think that is something that has been considered. At this point I'm going to put together a diagram of everything in the network and how it is connected (I wasn't in on the network setup from the beginning) - I want to make sure I understand how everything is working.
I'm sure I'll have additional questions once I do that. I just want to say thanks for your time in answering my questions, you have been very helpful.
Glad to help, if I can. Also consider that since the device is very, very old (upwards of 11 years which is positively prehistoric in tech terms), the embedded web server may be serving up pages that your modern browser considers as "invalid", leading to that error message. Depending in your browser, if this is the case, there might be some settings that control the browser behavior with such old websites, like HTTP 1.0 vs 1.1, etc.