[freebsd-network]why when OS reboot, my NIC status show no carrier

[wang_jiabo]

Hello, all:
    before freebsd show "hostname#", we can see NIC card status,
but my NIC card status always show "status: no carrier"
    after I login my freebsd , I used "ifconfig" command show my NIC 
card status is active
could have any skill  I can let my NIC card status show "status: active" 
before login freebsd.
my all the device connected with a switch, I setup my switch and freebsd 
is "speed 1000, and duplex full".

jiabo