1:1 NAT mapping potential problem?


Running Balance 305 HW2 with firmware 6.3.2. Router is used as the core router for a small wireless ISP. We have a /27 of public space on WAN 1. All internal IPs are private. When a customer needs / wants a static public IP, we assign them a private IP from VLAN50 (172.16.50.x) and then do a 1:1 NAT map of an open public IP to their now static private IP.

This seems to work. But I have one member with a problem I can’t seem to fix and it is pointing towards our Peplink… He is running a Plex server on his private network. His home router is set up to map port 32400 (TCP and UDP) to his IP of the Plex server. Plex is then available outside the network (in theory). His is not working. However, we have another user set up exactly the same way running a Plex server on the same port and his server is working from the outside world just fine on a different 1:1 NAT map.

We put his Plex server in his router’s DMZ. No change.
We then took away his home router, replaced it with a switch and had the Peplink serve him IPs from the 172.16.50.x VLAN. He gave his Plex server a manual IP that was then 1:1 NAT mapped to the public we assigned him. Still does not work. However, his Plex server can now be seen by other users on the internal 172.16.50.x network where it was not before.

Plex server is running on Ubuntu and there is no firewall running on that server.

We have one inbound firewall rule for the 172.16.50.x subnet that allows all connections from WAN1 (where the public IPs are). No other inbound firewall rules exist for that subnet or for the public IPs. Basically, that should allow all inbound traffic on our /27 through the firewall and then on to the 1:1 NAT maps, right?

Am I missing anything? Since it works fine for one user but not another, I am wanting to say the Peplink is not the issue but we are running out of things to test.


Another reason I’m looking at the Peplink? When he plugs his home router into a Comcast cable modem line, everything works perfectly for him. :frowning:


Please map another public IP to this user. If the problem still persists, please open ticket for us to take closer look. We shall able to catch the root cause.


I am having the same exact issue. I have 2 modems through Charter Spectrum connected to a Balance One Core. Each modem has a speed of 100/5. I am using Ubiquity AP’s that on a good day put out 200+ download / 10+ upload. I am not able to see PLEX outside my network. Any help would be greatly appreciated.


We confirmed the NAT Mapping is working fine on the previous case. You may perform Network Capture at http:///cgi-bin/MANGA/support.cgi to confirm the packet was reached on desired WAN and sent out from LAN interface.