I have a point & click type interface on a client (think RTS), which runs an A* on the server, for path-finding.

What is the best way to synchronize the player movements between the server and client, once I've computed the path(s)?

Does the server need to sync the clients on every animation step/frame? or can it just tell the client "go to position X,Y" for each node on the path, and each moving player? Or is it best to just run the animation timers on both client and server, and have it be implicitly synchronized that way?

What would the typical data-exchange be like for path-based movement?

I have a point & click type interface on a client, which runs an A* on the server, for path-finding.

The game is controlled like an RTS, but the world is persistent, so players should be able to join/leave at any time, and there will only be 30 or so units at most on the screen.

What is the best way to synchronize the player movements between the server and client, once I've computed the path(s)?

Does the server need to sync the clients on every animation step/frame? or can it just tell the client "go to position X,Y" for each node on the path, and each moving player? Or is it best to just run the animation timers on both client and server, and have it be implicitly synchronized that way?

What would the typical data-exchange be like for path-based movement?

EDIT:

Some of you have been suggesting lockstep, because I said "RTS", but the game isn't an RTS, it just has the same kind of interface. The big difference is I need to be able to have players join and leave the game at any time. Sorry for not being more specific.

I have a point & click type interface on a client (think RTS), which runs an A* on the server. What is the best way to synchronize the player movement with the server, from that point?

Does the server need to sync the client on every animation step? or can it just tell the client "go to position X,Y" for each node on the path? Is it best to just run the animation timers on both client and server, and have it be implicitly synchronized?

I'm wondering what's the typical granularity of synchronization required to make this work smoothly.

I have a point & click type interface on a client (think RTS), which runs an A* on the server, for path-finding. 

What is the best way to synchronize the player movements between the server and client, once I've computed the path(s)?

Does the server need to sync the clients on every animation step/frame? or can it just tell the client "go to position X,Y" for each node on the path, and each moving player? Or is it best to just run the animation timers on both client and server, and have it be implicitly synchronized that way?

What would the typical data-exchange be like for path-based movement?