Automount on NIS slave

I am setting up the NIS slave server to automount the home directory just like its master server on suse linux (SLES 10).
Since the master will be the first to mount the /home on the client. I have not been able to mount the /home on the on the slave when the master NIS server is unavailable.
How can i make sure that the slave NIS /home is mounted when the master NIs is down and also how to sync the two home directories when both servers are now up?