I am pretty sure that the problem I am experiencing is not related to my company’s Peplink Balance 20 but after many days of searching, I have given up and I am hoping someone on this forum might be able to point me to a source of information that helps.
I have a balance 20 connected to a single internet connection (no balancing currently) and an NAT address configuration of 192.168.1.X
I have 3 PCs running Windows 10 pro with RDP enabled on the default port of 3389 (do not want to change these because I do not want to mess with new windows security, and to be quite honest, I should not have to.)
The 3 PCs have static IP addresses 192.168.1.[250,251,252].
Within the LAN, I can RDP from any machine to either of the other 2 machines: 250->251, 250->252, 251->250, 251->252, 252->250, 252->251 all check out.
I have 3 inbound TCP port forwarding rules enabled on the Balance 20 for ports 3389, 13389 and 23389, pointing to 251, 250 and 252 respectively - the first is a single port 3389->3389 (which I would like to get rid of, in favor of another port mapped one) and the other 2 are port maps to internal port 3389 on the respective machines (i.e., 23389 port maps to 192.168.1.252:3389)
In the case of one of the machines, the port mapping work perfectly (i.e., RDP to router internet address @ port 23389 takes me to 192.168.1.252:3389) but the other two do not work with port mapping.
Additionally, the other 2 machines work with single port mapping (i.e., if I map inbound port 3389 to 250:3389, OR inbound port 3389 to 251:3389, I can set up external RDP sessions.)
I have checked firewall rules and windows defender on all 3 machines and they are identical.
So far I have compared the registry entries for Terminal Services on the machine that allows port mapped connections and one of the machines that does not and they are identical.
Does anyone have any other suggestions on where to look?