[CentOS] ISCSI and restarting the network

Is there a config file somewhere which I can edit which will automatically kill a specified process, and unmount a filesystem which is mounted over iscsi before shutting down the network, and then after the network is started to mount the iscsi mount point.

This is my /etc/fstab and the "/IMAP" device is the iscsi device

</etc/fstab> LABEL=/ / ext3 defaults 1 1 LABEL=/boot /boot ext3 defaults 1 2 none /dev/pts devpts gid=5,mode=620 0 0 none /proc proc defaults 0 0 none /dev/shm tmpfs defaults 0 0 /dev/sda3 swap swap defaults 0 0

LABEL=/IMAP /opt/test ext3 _netdev 0 0