I'll state yet again
When you are doing a client mod... ALWAYS copy your l2 client folder and mod the copied one
Example
original retail install = C:\Program Files\Lineage2
Client mod install copied to = C:\Program Files\C4 Lineage2 (or where ever you want to move it or to call it)
then if you make a mistake on the copied folder you can just delete it and recopy the already updated retail version. And that way if a retail update comes out, you can update the retail one to test with new server versions as well as have your currently working client and server
MariosX what brand of router do you have?
and I sent you a PM in reply, just waiting for some feedback
(edit)
upon reading back on the 2nd page of this I saw in your post
Hostname for external connections is: 62.1.250.211
Hostname for internal connections is: 62.1.250.211
it looks like you have your WAN IP set to your internal connection...
this has to be a local LAN IP address... if you are connecting to the server from the same PC hosting it, 127.0.0.1 is what you need to use, if you want your friends to connect then you must use your LAN IP which can be found by running
Start>Run and typing cmd, then in the prompt type IPCONFIG
your IP will be something like 192.168.x.x
use THAT IP in there
As well... make sure your hosts file is set properly... and YOUR hosts file will differ from your friends who are connecting
host file internal connections ( for you and LAN computers)
192.168.x.x l2authd.lineage2.com
host file for external connections (your friends)
62.1.250.211 l2authd.lineage2.com
(Change X's to your LAN IP)