We're going to need more information than that.  You tried what?  And what did you expect the outcome to be?  What have you done to debug the issue?  Etc...  The more information the better.

I assume every animation has a "current play position" parameter, to allow seeking?

When animations start playing, and while they're playing, you should probably keep sending packets of "animation X is playing, at position Y when the game time is T." On the client, receive those, and make sure the animations sync up to animation-position / game-time. When animations stop playing, of course send a packet saying they aren't playing anymore (and, if you're using lossy packets, keep sending until you're sure the client knows.)