Zandronum

Hello guys,
I can't create a server and I feel so stupid :'(

I've installed Zandronum and now I can:
- play alone
- play a dethmatch with some bots
- choose maps ecc ecc

I can't:
- play with friends
- create a server online (my friends don't see my server and when they create it I can't see his server)
- remove a server (In doomseeker there are 2 servers that I can't remove!)
- Change a server (I want to modify characteristics of a server but I can't)

What I have done:
- Install Zandronum
-"create game"
- Choose wad, port 10666, choose name serve ecc
- Start server
- NETWORK_Construct: Couldn't bind to 10666. Binding to 10668 instead...
IP address 192.168.0.100:10668
GeoIP initialization failed.
UDP Initialized.
Error adding port mapping: Fail to add port mapping (test/UDP)

I see my servers in light blue. They told me I have to go to custom server and so I add one with my Ipv4, Then In doomseeker I can see it with a yellow background instead of light blue. I don't know if my friends can see it. However I can't change map or game type. With right click I see "refresh, join, show join command line ecc"
Finally I don't see my Italian Flag but 2 monitors. One time I've seen a pc.

I don't know what to do. I'm going to destroy pc. Please help me.

Cheers and thanks

Show us a screenshot of your server settings in DoomSeeker (before you create the server) and how you've port forwarded Zandronum.