I have a SMB network mount in /etc/fstab, which is supposed to be mounted at boot time. This fails most of the the time with errors like these:
CIFS VFS: No response for cmd 114 mid 1
CIFS VFS: cifs_mount failed w/return code = -112
I am fairly certain this is being caused by /etc/fstab being processed when the network isn't up yet, because mounting the share manually afterwards always works.
The regular mount command has the _netdev mount option, which tells mount to hold on until the network has become available.
IMHO it would be a good thing if mount.cifs grew this option too.
Actually... /bin/mount doesn't do anything with _netdev, it's ignored. That's intended for use by init scripts (at least according to Karel Zak, the util-linux-ng maintainer).
Current versions of mount.cifs and the kernel also ignore it.