Networking gods of AT, please help me with

[konakona]

Currently I am at parents place in Texas, enjoying the breezy weather and everything I left my computer at home on so I could pull files off of it or remotely initiate downloads which works like a charm.

My parents arent the most brilliant people when it comes to computers, and it really would save them lots of trouble if I could provide them support using UltraVNC or Radmin. Unfortunately, things arent working too well as I would have wished for.

UltraVNC reports it cant connect to the server when I try to access my parents box from my place, pretty much the same result for both Radmin and XP's built-in remote desktop. I made sure ports 5800-5900 were forwarded properly, and the CSR from the ISP reassured me they arent blocking anything either. SP2's firewall has never seen any use on either of the machines, and I even attempted turning the router's firewall. It cant possibly be the dynamic IP issue, since I have tried coordinating with my parents over the phone all in vain.

What else is there to check? I just find it odd it only works one way, not the other way around. TIA.

 

[Fardringle]

Can you connect to the parents' computer while on their home network (say from a laptop)? If so, then VNC is working on their computer and it's a forwarding issue on their router or with the ISP. If not, then it's a problem with VNC on their computer (could also be a software firewall but you said they don't have one).

 

[konakona]

Originally posted by: Fardringle
Can you connect to the parents' computer while on their home network (say from a laptop)? If so, then VNC is working on their computer and it's a forwarding issue on their router or with the ISP. If not, then it's a problem with VNC on their computer (could also be a software firewall but you said they don't have one).

Yeah, it works just fine within the LAN at our place. I was suspecting the ISP, but the CSR doesnt seem to think there would be anything on their side. The ruoter in question is WRT54GC and TCP port 5900-5900 is forwarded to the corresponding internal IP address.
Again, nothing wrong with VNC on their computer as I can connect to it no problem from another computer belonging to the same network. What gives?

 

[TheSophist]

I'm not sure if you made a typo, but if you forward port range 5900-5900, it will actually deny that port. Instead, try 5900-5904, or even better 5800-5904. Also, you said that you were coordinating with your parents on the dynamic IP. How are you getting the public IP from them?


TheSophist

 

[JackMDS]

To connect through the Internet you need to be outside of the system, you can Not type the extrenal IP and connect inside out and inside.

:sun:

 

[Pheran]

Originally posted by: JackMDS
To connect through the Internet you need to be outside of the system, you can Not type the extrenal IP and connect inside out and inside.

This is not true of all routers. This actually works with my WRT54GS. I can access my internal webserver from clients on the inside network through the router's external IP. The router actually source NATs my connection to its internal IP to keep itself in the traffic path - smart little ah heck.

 

[Pheran]

Originally posted by: TheSophist
I'm not sure if you made a typo, but if you forward port range 5900-5900, it will actually deny that port.

This does not make any sense. Forwarding a range that includes only a single port is a perfectly legitimate configuration. That's how my SSH, SMTP and HTTP servers are all working right now.

 

[konakona]

Just tried it again, and I do get "failed to connect" error message between two machines inside the lan with external IP address for the server. Maybe port forwarding wasng configured properly after all? Again, there is no active firewall in the path and the ISP confirmes that all ports are open. 5900-5900 should work fine, thats how I have it setup at my own place IIRC.

 

[Pheran]

Originally posted by: VanillaH
Just tried it again, and I do get "failed to connect" error message between two machines inside the lan with external IP address for the server.

As Jack said, this is a dubious thing to try. Accessing the external port forwarding from the inside network is certainly not guaranteed to work with all routers. The only way to truly test this locally would be to insert a hub or switch between their router and modem, plug a PC into it and temporarily "steal" an IP that falls into the whatever external subnet you are getting from the ISP (this might not work if you're using PPPoE). If the external IP works from there, then the ISP is almost certainly blocking your traffic.