Servers drops new connections from IP

[Hint]

I am working on a new protection for game server. Protection based on proxy-server, that encrypts all packets and do many other things. Sheme:
Client <-> Proxy <-> GameServer
All connections for game server have the same IP (127.0.0.1 or another).
All works fine... but suddenly GS begins to drop all new connections from proxy-ip (connections accepted, but closed after first incoming byte).
There are no messages in L2J console.
It looks like AntiDDOS function, but I can't find something like that in configs or in sources.

Maybe reason not in L2J, but in Windows Server? But there are no external firewalls or limitations...

[Hint]

Is there any AntiDOS function in L2JServer, that can drop new connections from specific IP?

[blacksea]

im not very sure but try to check if 127.0.0.1 its not blocked by LS

like Banning '127.0.0.1' for 600 seconds due to 10 invalid user name attempts since you have same ips for all.. its possible

[Hint]

Proxy works only with Game Server. Client directly connects to AuthD (without proxy).

[Hint]

It looks like IPv4Filter:
http://svn.l2jserver.com/trunk/L2J_Serv ... ilter.java
Is there any options in configs to disable this filter? Or this filter is hardcoded?

[Hint]

It's stupid to ban localhost Author should exclude 127.0.0.1 in check method.