I'm using "NetBSD 1.6ZG (GENERIC.MP)" which
is a stale version of -current.

My DHCP server is Windows 2000 server.

My "/etc/rc.conf" contains:

	dhclient=YES
	dhclient_flags="fxp0"

My "/etc/ifconfig.fxp0" contains 1 line:

	/etc:$ cat ifconfig.fxp0
	up
	/etc:$ 

and I've never had a problem:

	/etc:$ ifconfig -a
	fxp0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	        address: 00:d0:b7:a7:34:6d
	        media: Ethernet autoselect (100baseTX full-duplex)
	        status: active
	        inet 192.168.41.22 netmask 0xffffff00 broadcast 192.168.41.255
	        inet6 fe80::2d0:b7ff:fea7:346d%fxp0 prefixlen 64 scopeid 0x1
	lo0: flags=8009<UP,LOOPBACK,MULTICAST> mtu 33196
	        inet 127.0.0.1 netmask 0xff000000
	        inet6 ::1 prefixlen 128
	        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x2