When user attempt to set network or broadcast address, ask again for the IP address. Issue #3196
Add function is_inrange() that calls is_inrange_v6 or is_inrange_v4 accordingly
Check if dhcp start and end addresses are inside interface subnet, helps #3196
Unbreak etc/sshd, add a missing quote
Add a knob to prefer IPv4 over IPv6, it fixes #2833
Load only the options and nothing else