Remove call-time pass-by-reference
Fix logic of is_inrange()
Move is_inrange() to util.inc and rename it to is_inrange_v4()
Fix logic of v6 version of is_inrange()
Move is_inrange() to util.inc and rename it to is_inrange_v6()
Ensure DHCP main range, pools ranges and static IP addresses don't overlap each other. It should fix #2773