Friend has a private server

[Ertyjim 1]

We all got sick of hackers and scripters, so awhile ago he made a private server. We all got in fine, but after a little while of playing, the server ping got too high since he had bad internet. So, he got better internet and then when he did it again, it didn't work for me. It worked for other people, but not me. Please help!

[Ertyjim 1]

Anyone?