Routing/Login server issue

[Eboonysa]

Hi ppl.

I'm not sure if this is a routing issue or a login server problem.

Having an issue with outside connections to my login server.

When I connect from within the LAN, I can log in many accounts, no problem.

However when people connect through router they get a connection error if they try to log in a second account.
Also if they log out they have to wait for the session to time out to re-connect.

Ports are forwarded, World:MaxClientsPerIP is -1.

Using Wireshark I can see the packages coming in, so I think it's not the router.
In the login_xxxx.log file I just get this:

[Network] [04.03.14 - 16:30:35] Client disconnected from the server, removing client.
[Network] [04.03.14 - 16:30:58] New SoD client connection from EDITED-IP:49854
[Network] [04.03.14 - 16:30:59] Client disconnected from the server, removing client.
[Network] [04.03.14 - 16:31:27] New SoD client connection from EDITED-IP:61887
[Network] [04.03.14 - 16:31:28] Client disconnected from the server, removing client.
[Network] [04.03.14 - 16:31:47] New SoD client connection from EDITED-IP:61888
[Network] [04.03.14 - 16:31:48] Client disconnected from the server, removing client.
[Network] [04.03.14 - 16:32:30] New SoD client connection from EDITED-IP:59853
[Network] [04.03.14 - 16:32:31] Client disconnected from the server, removing client.
[Network] [04.03.14 - 16:35:59] New SoD client connection from EDITED-IP:50895
[Network] [04.03.14 - 16:36:00] Client disconnected from the server, removing client.

Never gets to the application packet received from client( size 12 ) part :/

Anyone experienced this issue before?