IP Addresses

But I don't see anything (obvious) in the Modem's setup page allowing me to do port forwarding... Its available on the router configuration page alright... I guess I need to get these two black boxes talking correctly to each other...

Ah ... now I see the problem. To get through to your observatory PC from the outside world you need to traverse two routers. The Modem is DEFINTIELY doing NAT, the router MAY be doing NAT. If you can't do portforwarding on the first step, i.e. the modem then the traffic cannot get to router to be forwarded any further. Think of it as water trying to flow down hill through two locks. You've opened the second lock but not the first so naturally no watter is flowing.

I'm at a loss as to why you need a router AND a modem. This seems like a very strange setup. If the modem doesn't do portforwarding then you need to replace it. I'd suggest you replace it with a more default configuration and just get a single ADSL router which can do everything for you.

Hope that helps,

Bart.

I'm at a loss as to why you need a router AND a modem. This seems like a very strange setup. If the modem doesn't do portforwarding then you need to replace it. I'd suggest you replace it with a more default configuration and just get a single ADSL router which can do everything for you.

I need a router and a modem because my modem only has one ethernet port and no wireless

Mind you I have everything on the one subnet which makes life easier.

I'm at a loss as to why you need a router AND a modem. This seems like a very strange setup. If the modem doesn't do portforwarding then you need to replace it. I'd suggest you replace it with a more default configuration and just get a single ADSL router which can do everything for you.

I need a router and a modem because my modem only has one ethernet port and no wireless

Mind you I have everything on the one subnet which makes life easier.

Then you need a switch! not a router! The two are very very very different things!

Then you need a switch! not a router! The two are very very very different things!

No no, I need a router. Just trust me ok
Maybe I lied a little when I said it was all on the same subnet

My DSL modem has the two address - private and public (LAN and WAN) alright. But I don't see anything (obvious) in the Modem's setup page allowing me to do port forwarding... Its available on the router configuration page alright... I guess I need to get these two black boxes talking correctly to each other...

Dave, you should be able to get it working by using modem port forwarding to the WAN address on the Router to the same port (to keep things simple).
You then get the router to forward that port to the PC.

Michael.

Mike - I tried that but to no avail....

What I did try, and it caused major problems, was to change the router address.

The DSL modem address is 192.168.1.1 so I made the router 192.168.1.50 This casued serious problems so I reverted the router back to its original address.

I messed about with the modem NAT table to try and get it to see either the router or the Observatory PC - to no avail. The Obs pc is now given a static address by the router - so I thought that might help...

I've tried every combination of DSL modem address, port forwarding addresses, NAT addresses I can think of. I think I'm ready to call it it a day and invest in a combined DSL modem/router.

Anything in particular I should be wary of or features I should demand?

Cheers
Dave