I have 8 WAN IP addresses assigned to my connection. One of those IPs forwards all Remote Desktop (TCP port 3389) traffic to an internal IP address.

Using this IP address externally, I can connect via RDP to the workstation no problem.

Internally however, I can ping the WAN IP, but cannot connect using RDP.

It's not just RDP - it's anything.

Any idea what would cause this? The DoS Protection is disabled and SysLog doesn't show anything when trying to connect via the WAN IP address internally.

I'm using firmware version 3.3.3_211801.

I've read elsewhere that this is something of a know issue with the 2820 - it doesn't properly support loopback.

Having said that, I've managed to get it working on mine. My setup is:

WAN1 Internet Acces, WAN IP Alias - I have each of my assigned external IP address set up

In NAT Port Redirection, I have TCP Port 3389 set up to redirect from all external IP address

And that's it. No open ports, no address mapping. I'm on firmware 211801 Annex A

Hope this helps

Thanks Nick. I found the problem in the end... IP Routing... For some reason having IP routing enabled prevents any external IP address from reaching any subnet you have configured with the routing - in our case we had:

1st IP: 10.10.1.0/255.0.0.0
2nd IP: 10.1.1.0/255.255.255.0

We did this because we had certain hosts on a different subnet to everyone else, so having this setup meant everyone could see one another.

That said, we were only talking about a handful of hosts on the 255.0.0.0 subnet, so I turned off IP Routing and changed them to the other subnet, and it worked.

Isn't this a firmware bug though?

Gald it's working

I suspect it is a firmare bug - this didn't seem to be an issue on the older 2800