ifconfig says that the status of re0 is "no carrier"

ifconfig says that the status of re0 is "no carrier"

re0: flags=8802 metric 0 mtu 1500
 options=389b
 ether 00:16:36:7f:6e:b6
 media: Ethernet autoselect (10baseT/UTP )
 status: no carrier

[] We have to use that special parameters with ifconfig because our switch does not support autoselect.

[] You can add those mediaopt options to ifconfig_re0 in rc.conf:

# iv /etc/rc.conf
ifconfig_re0="inet 192.168.1.5 netmask 255.255.255.0 media 1000baseTX mediaopt full-duplex"

[] Other than that, 'no carrier' is usually 'no cable' or a dead/downed switchport.

[] Which could happen if you get lots of duplex and speed mismatches, a switch might decide to block off that port. On proper equipment I'd set both on both sides, never auto negotiate. Most unmanaged switches are a bit tricky though. And realtek isn't the best either. I know my realtek cards and home el-cheapo sweex switch will throw a fit if I don't use auto/auto.

[] restart freebsd networking service:

# /etc/rc.d/netif restart && /etc/rc.d/routing restart

# /etc/rc.d/netif forcerestart && /etc/rc.d/routing forcerestart

[] pciconf -lv

re0@pci0:3:0:0: class=0x020000 card=0x2aa9103c chip=0x813610ec rev=0x05 hdr=0x00
    vendor     = 'Realtek Semiconductor'
    device     = 'Realtek 10/100/1000 PCI-E NIC Family all in one NDIS Driver v5.728.0604.2009 06/04/2009 (Rtl8023)'
    class      = network
    subclass   = ethernet

http://gala4th.blogspot.com/2011/01/freebsd-set-speed-duplex-for-my-network.html