Solved Server isn't working on the PF IP

I have changed my server's ip address to "___.no-ip.biz" (sorry, its very insecure ATM)
I have it on port 25566 because I already have another server running on port 25565.
I used no-ip to have a free host, and when setting up my host, I used settings-
IP: <MyIP>
Port: 25566
Type: DNS Host A
I configured everything with my router, and everything should be working fine, but when I run "startserver.bat" it gives me errors:

08:16:16 [WARNING] **** FAILED TO BIND TO PORT!
08:16:16 [WARNING] The exception was: java.net.BindException: Cannot assign requ
ested address: JVM_Bind
08:16:16 [WARNING] Perhaps a server is already running on that port?

I'm pretty sure that I only have 1 other server, and that its running on port 25565.
Although, when I leave the IP address blank or type localhost in the IP address section, it works. Does this mean that there is something wrong with my port forwarded IP?
Please tell me what else I have to do if I want people to be able to connect to my Port Forwarded IP

 

Don't put an IP for server-ip= in server.properties. Just leave that blank

 

If you are using linux, you can look at the process bindings by issuing : netstat -tap

 

Thanks I'll ask my friend if he can connect to it. If it works, I'll make this topic solved

YES!!!! It worked! Although, he had to connect to <PFip>:25566 (port 25566) for it to work. Is this normal?
I'll say solved though, since it did work

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

If you don't specify the port, it will automatically choose 25565, so you'll have to specify the port, if it's not 25565 (such as 25566).

 

Thanks