Windows Server 2008 R2 weird ip blocking problem

[mLgz0rn]

Hey everyone.

 

We got an issue with our Windows Server 2008 R2.

 

we are hosting some Counter-Strike servers from it.

the problem is, people with an ip that starts with "77" can't join our server.

 

so we tried a few things, i made an allowlist in the firewall but that didnt help.

now, one of my mates has 2 servers in the same hosting center as our server, 1 that runs on the same network as mine and 1 that runs on another.

 

and just to inform you guys, my ip on the server also starts with 77, same for my mate.

 

so when he tries to ping our server from the one on the same network it works fine.

but when he tries from the one outside the network, he gets timed out.

 

the only firewall our server is behind is windows firewall, nothing else.

 

i tried to disable the firewall completely, just to see if that was the reason.

but he still couldnt ping the server from the one outside the network.

 

it's only people who have an ip that starts with "77" that gets rejected, anyone else can ping our server and join our Counter-Strike Servers

 

Please help.

 

sorry for my bad english.

and please ask if you need more information

 

and please move the topic if i posted it the wrong place, didnt know where to put it.

 

Best Regards

[F2 Staff]

This very well could be a problem at the border router and not with the server itself.

 

Have you contacted your host and ask them if they are doing some sort of filtering at the router?

[mLgz0rn]

hey, sorry for the late answer.

 

i talked to my mate and he said that we are not sitting behind any router, only a switch.

so we got a static ip on the server.

 

not any of the other servers in the hosting center got this issue, which means that it can only be a problem on our server.

 

so i don't know if there is happening some sort of conflict or something? :S its really weird

[ICTCity]

be sure that there's no router or firewall because usually this problem occurs when something is misconfigured. Maybe the problem is that all the network starting with 77 are considered as the server, this will block the proper communication.

[mLgz0rn]

heya.

 

just gonna inform that the issue is solved.

found out that my mate had set the server up running with the wrong subnet mask.

 

it was running 255.0.0.0 instead of 255.255.255.192

so it's all good now :-)

 

thanks for the replies guys