Why won't my minecraft multiplayer server work for other people?

I know minecraft multiplayer went out yesterday for a bit but when I get on its fine cause I own the server but when others try to get on it says "pinging" or can't reach server and this is the first time this has happened. Also when they connect it says lost connection but they could connect before. So I think maybe there's a new update or I messed it up without touching it. Any ideas?

Added (1). I have port forward already,

Added (2). Not a bukkit server, And I don't want to delete the server. I think its just cause minecraft went out yesterday

Abby

Have you portforwarded?

Try re-installing the server?
Are you using Bukkit?

Guest

Has there been a change in your IP or IPv4 address?

If you've port forwarded, this counts if you've forwarded to a specific computer. Re-check the computer's IPv4 and change the forwarded computer address to match it. If your server is managed via DNS, make sure the public IP remains correct.

The IPv4 issue can occur if you either use another computer to host the server/frequently change the host computer, if the network has been reset, or if your computer has had its address reassigned in the network, changing the IPv4 (or something to that effect). This depends on the router's port forwarding methods so this may or may not be the case.

Best of luck getting it back up!

Guest