I'm playing with a FreeBSD VM. I'm more accustomed to Linux, which doesn't need /etc/networks as far as I'm aware.
Nik Clayton's FreeBSD Network Administrators Guide says this about the /etc/networks file:
"Just as with a host's IP address, you should sometimes use a symbolic name for network numbers, too. Therefore, the hosts file has a companion called /etc/networks that maps network names to network numbers, and vice versa."
It goes on to give an example of use, but it doesn't explain when or why the /etc/networks file would ever be used.
I notice "man 5 networks" at the FreeBSD website mentions DARPA, which suggests it's a very old file format. The Linux edition mentions netstat and route, which are still used on FreeBSD. This suggests there might be some sort of dynamic routing use for /etc/networks the same way we use /etc/hosts in combination with DNS?
Is there a purpose to /etc/networks? Or is it just a legacy artifact of old FreeBSD versions that hasn't been removed yet?