Here's an /etc/exports that will export the same filesystems as the one in the previous panel, except that it will make my exports available to all machines on my LAN -- 192.168.1.1 through 192.168.1.254:

# /etc/exports: NFS file systems being exported.  See exports(5).
/ 192.168.1.1/24(rw,no_root_squash)
/mnt/backup 192.168.1.1/24(rw,no_root_squash)

In this sample /etc/exports file, I use a host mask of /24 to mask out the last eight bits in the IP address I specify. It's also very important that there is no space between the IP address specification and the "(", or NFS will interpret your information incorrectly. And, as you might guess, there are other options that one can specify besides "rw" and "no_root_squash"; type "man exports" for a complete list.