dmesg
と/var/log/messages
に以下メッセージが出ます。
[ 75.816550] e1000: eth0: e1000_watchdog: NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
[ 75.817003] ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 76.800009] eth0: duplicate address detected!