Port Forwarding behind two routers?

[Uddhav_GT]

I want to port forward to a port to my pc which is behind two routers. How do i do it ?
I know the general idea about what I have to do to achieve it but I don't know how do I find out each router's internal and external IP address.
the router/modem that my ISP gave me is a Alphion ARGT-1000 VDSL router and I have a Linksys EA6400 that I have connected to my pc.
SO I have this port that I have to forward but can't find each internal and external IP addresses. Can anyone help me with it.

I have a picture of my home network attached.
See if that helps any.

[aidenrelkoff]

thata uuuu, wow. yeah, cool.

 

umm no idea, i also am behind a modom, router, and a switch, and im having troubles too, if i find a solution, let let you know.

[aidenrelkoff]

yout internal is your ipv4 adress, open cmd and type in ipconfig. external is like 70.66.99.108

[Helios79]

Instead of trying to figure out how to port-forward in a double-NAT, it would be advisable to find out if the gateway (yes, gateway, not router) can be placed in bridge mode. Some gateways do support this, and some do not. Your only other alternatives are to throw the Linksys into a DMZ (disable the firewall) or disable the routing functions and use it as a switch. Bridge mode will turn your gateway into a modem-only device and will disable the NAT built inside.

[Uddhav_GT]

Helios79 Dosen't seem that I would disable my network's firewall.

[Uddhav_GT]

yout internal is your ipv4 adress, open cmd and type in ipconfig. external is like 70.66.99.108

Seems I have got all the IP addresses figured out, but my issue now is that the Modem/Router that I have (Alphion ARGT-1040) and as I am not familiar with a lot networking terms I am confused how should I port forward the 'First LAN' (i.e. The network between the Alphion Router/Modem and the Linksys Router).

In the NAT drop-down of my Alphion Router/Modem setup there are two options, Virtual Servers and Port Trigger.

Which on of the two is the one for Port Forwarding?

Is it the Virtual Server?

Or is it Port Trigger?

[Uddhav_GT]

Got it working!
Thank You two guys.
I get both the internal IP Addresses. the modem's from the modem status and the linksys one's is easy to get in the similar manner.
Next I Port Forwarded the Modem/Router from the Virtual Server option with the Server IP as the Internal IP of the Modem/Router and then did the same with the Linksys Router, added the port range (In my case, just one port) and the Required IP as the PC's External IP Address which I got by running cmd and then ipconfig then the Default Gateway.
It was easy.
And thank you again guys.
Just a Linus says, LTTF is the best.
And Linus is the bestest