ifconfig_*="DHCP" in absence of server

[Gleb Popov]

At $WORK I'm running a bunch of similar FreeBSD machines, all of them have

ifconfig_DEFAULT="DHCP"

in their /etc/rc.conf

The DHCP server runs on some old Cisco router.

At the start of the working day the power switch gets turned on and both
the router and FreeBSD machines start simultaneously. FreeBSD boots faster
than Cisco, but then hangs on "netif" rc script trying to acquire an IP
from the router. It waits for more than 30 seconds before giving up and
proceeding, and even after that the "routing" script blocks for another 30
second with "waiting for default route". This delays the time needed to
reach the X graphics stage for too long.

Funny enough, "SYNCDHCP" option shortens this time, but it is still visible.

Is there any way to make DHCP acquisition asynchronous, or something else
to speed things up?

Thanks in advance.