Bad Subnet Kills DHCPD

One, single bad IP in DHCPD config will kill the entire config file. :(

On an EdgeRouter, and probably anything with Ubiquiti, and maybe anything using the same config style (Brocade and others have the same command set)….

If you add a static reservation outside of the DHCP server’s subnet,
as in, if you typo one octet, or decide to do another subnet just because,
your DHCP server will be offline after reboot. No errors, just silently not serving.

It can be outside of the start/stop range, and that’s fine.

Really, this should give you a warning from the webUI, or it should just say “OKAY, We’ll let you hand out stupid IP addresses.” I mean, what if I wanted this to be my DHCP server, but I had a different router and subnet on the same segment?

From command line, you’ll see the error though:

admin@gw1# commit
[ service dhcp-server ]
Static DHCP lease IP '' under mapping 'CustomerLaptop'
under shared network name 'LAN' is outside of the DHCP lease network ''.
DHCP server configuration commit aborted due to error(s).