Originally Posted by Kiros
Oh, Forrest, if both of your routers have the option, try configuring your first router to have a DMZ host (being the second router), and the second router having one too (being your computer).
Only do this if you don't have any other computers on your network that you have intentions of Hosting anything on.
Like, if you only have one Device connected to the Modem (Router 1) then DMZ for the Modem is Fine. If you only have one Device connected to Router 1, DMZ is fine for Router 1. But, if you have 2 Devices on Router 1 that you want to host something on, Say RDP (Remote Desktop) on Computer A and HTTP on Computer B, don't set up DMZ on Router 1.
Otherwise, Setting up DMZ will make it easier.
Originally Posted by Kiros
Also, there might be some kind of configuration you need to properly set in one or both of the modems (could be firewall, restrictions, or general networking options).
Here's a fairly large listing Howto set up Port forwarding for Specific Services on a large list of Routers.
Which, Sometimes shows you other changes you might need to make, such as Firewall Changes. Although, it just depends on if your routers are listed, and your exact configuration.
I don't believe it's necessary, but Port 20 (FTP Data Port) MIGHT also be needed. I'm pretty sure you don't need to forward this port, but I'm not positive. Most Configs on Routers only tell you to forward port 21 for FTP, so it might not need to be forwarded in order for FTP to work correctly.
So, if all else fails, try forwarding this port as well. Although, if it's not needed, it'll just add another security vulnerability having that port set up on your router/server.
EDIT: Also, if you don't have any specific reason for using both Routers as DHCP Servers, you could disable Take router 2 and disable DHCP and have it run passively and just bridge the two connections together. So, basically, what you'd have, is Router 1 controlling EVERYTHING plugged into Router 2, so you'd completely bypass any need to configure router 2. You'd have to have Router 1 connected from a LAN port on Router 1 to a LAN port on router 2, instead of into the WAN port on Router 2.
Depending on what you have, you might need a Crossover cable for that to work though.
But don't use that unless all else fails. I used that set up a little while back when I was running more then one router. There's not much of a point in running two-three seperate DHCP Servers hosting IP addresses if it's not needed. It'll just cause more problems. Besides, you won't be able to access a computer very easily that is on a different router then your computer as you normally would, since everything's going through the WAN port. Cutting one factor out of the Equation just simplifies the entire thing, causing less headaches.