Terminal Servicing in to another computer on the same ISP doesn't work

[rdnkjdi]

I have a strange problem ... I've done a lot of networking stuff (but there are things I don't fully understand about exactly what is going on).

I have a customer and I set his office up to allow remote desktop connection using port forwarding and dyndns. I tested it from my office in a city 200 miles away - and it works fine. But when I use his computer to try to TS into his office computer - it doesn't work. Looking a little further - when I do a tracert it is trying to hop through his local router - the packets never make it to the WAN - it keeps using his gateway to try to resolve.

So it might look something like this

Office IP is 44.55.66.77
Home IP is 44.55.66.78
Home router internal IP is 192.168.0.1

tracert 44.55.66.77 returns "request timed out" and is using 192.168.0.1

What is going on here?

 

[imagoon]

The router probably isn't allowing the connection to wrap around back inside. Some need to have this turned on, some simply don't have that option.

 

[rdnkjdi]

Any way you can describe to me what that option might look like? Is there any way I can set up a second external ip address outside the isp that that forwards it to the first?

 

[imagoon]

It is called NAT reflection in some devices.

--edit--

I also have seen NAT loopback. Forgot that one.

And while yes you could bound off another IP somewhere, it really isn't necessary in most cases. You could either a) use the internal IP b) route between the internals and still do a. c) get a NAT device that actually works for you are doing.

 

[kevnich2]

If you're using computer A and trying to RDP to computer B, is computer B on the same network or a different network (Are they both using the SAME gateway/firewall)? Or are they simply using the same internet provider (eg both on verizon for internet)? If both systems are on the same network, meaning both are connected to the same firewall/router/gateway device, you'll either need to RDP to the local private IP or create a NAT rule to essentially do a loopback - instructions are totally dependent upon what firewall you are using.