Network Access through Cascaded Routers

[FrankCCsw]

We have an unusual assemblage of routers providing three LANs from of a single WAN connection. Two routers cascade off the first router to form two LANs; the fourth router cascades off one of those first LANs to form a third LAN.

The overall system is configured in this unique way for a series of reasons I won't bore you with now.

Internet access originated on any of the LANs works fine, even the third LAN that's spurred off one of the first two LANs.

What we need to do, however, is come in from the WAN and log on to specific devices that might be on any of the LANs.

I have the IP address of the WAN, which gets me to the login page of the first router.

What I'm having trouble figuring out is how, from the WAN, to get through the routers and address specific devices on any of the LANs. (Ultimately, the third LAN is devoted to IP security cameras; each cam is capable of supporting a login -- if I can just get to them.)

1. I assume a port number is required when addressing, something like this:

<WAN IP address>:<Port Number>

and that I at least need to open that specific port number on the first router.

But then, is there a way to have that first port number linked (forwarded?) to ports on each the serially cascaded router(s)?

Will router port forwarding work for something like this? Should I use DMZ?

At this first cut, I'm looking for some conceptual help on how to get started on this; even some examples or other places to look.

Thanks,

Frank

 

[RaDiKaL_]

Is NAT enabled on each router? or just in the border router(the one that provides Internet to all your networks)? depending on that the config to apply will change completely.

 

[bill001g]

It is pretty much as you describe. You just port forward on each router pretending the cascaded router is actually the end device. When you get to the lowest router you will have a port forward to the actual device. It is mostly just being careful to get the ip correct. For example the main wan router would not port forward to the ip of the actual device it would port forward to the wan ip of the cascaded router in the path.

 

[thently]

Yes just use port forwarding make a rule in gw router to point to internal router wan IP then make another rule in 2ndary router to point to the computer in question. I will say this will put that computer open to the world if you leave this rule open all the time. If they can guess your RPD password you might have issues. Just FYI.