isc-dhcpd refuses access?

[Zaphod Beeblebrox]

So... my home router has a trunked relationship to the home switch.

BGE0.31 is the guest network and has 172.17.31.1/24.

BGE0.221 is the home network and has 192.168.221.1/24.

Now on the switch, the "access" (untagged) VLAN is 1.  This works: BGE0 is
192.168.110.1 and the switch's management is 192.168.110.253.

Recently, I've been playing with a new switch, and only wants to talk on
vlan1.  I can see it's DHCP requests on the untagged port, so I modified my
isc-dhcpd configuration to include a subnet and range for 192.168.110.0/24.

Oddly, however, when restarted, dhcpd says it is listening on bge0.31 and
bge0.221, but ignores bge0.  Help?