linux服务器网线没插的日志分析

  今天，根据客户需求，给一台服务器安装centos 5.6的系统。安装之后配置IP，发现连接不上网，ping不通网关，于是开始检查 1.网卡配置。正常 2.检查网卡驱动，正常。

  于是开始查询日志发现以下报错：

tail -f 100 /var/log/messages

Jun 17 14:47:22 server140 kernel: ADDRCONF(NETDEV_UP): eth1: link is not ready
Jun 17 14:47:23 server140 kernel: bnx2: eth1 NIC Copper Link is Up, 100 Mbps full duplex
Jun 17 14:47:23 server140 kernel: ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready
Jun 17 14:47:25 server140 avahi-daemon[2239]: New relevant interface eth1.IPv6 for mDNS.
Jun 17 14:47:25 server140 avahi-daemon[2239]: Joining mDNS multicast group on interface eth1.IPv6 with address fe80::baac:6fff:fe93:213f.
Jun 17 14:47:25 server140 avahi-daemon[2239]: Registering new address record for fe80::baac:6fff:fe93:213f on eth1.
Jun 17 14:47:26 server140 avahi-daemon[2239]: New relevant interface eth1.IPv4 for mDNS.
Jun 17 14:47:26 server140 avahi-daemon[2239]: Joining mDNS multicast group on interface eth1.IPv4 with address 192.168.1.140.
Jun 17 14:47:26 server140 avahi-daemon[2239]: Registering new address record for 192.168.1.140 on eth1.
Jun 17 14:48:51 server140 avahi-daemon[2239]: Withdrawing address record for 125.76.225.140 on eth0.
Jun 17 14:48:51 server140 avahi-daemon[2239]: Leaving mDNS multicast group on interface eth0.IPv4 with address 125.76.225.140.
Jun 17 14:48:51 server140 avahi-daemon[2239]: iface.c: interface_mdns_mcast_join() called but no local address available.
Jun 17 14:48:51 server140 avahi-daemon[2239]: Interface eth0.IPv4 no longer relevant for mDNS.
Jun 17 14:48:51 server140 avahi-daemon[2239]: Withdrawing address record for 192.168.1.140 on eth1.
Jun 17 14:48:51 server140 avahi-daemon[2239]: Leaving mDNS multicast group on interface eth1.IPv4 with address 192.168.1.140.
Jun 17 14:48:51 server140 avahi-daemon[2239]: iface.c: interface_mdns_mcast_join() called but no local address available.
Jun 17 14:48:51 server140 avahi-daemon[2239]: Interface eth1.IPv4 no longer relevant for mDNS.
Jun 17 14:48:51 server140 avahi-daemon[2239]: Withdrawing address record for fe80::baac:6fff:fe93:213f on eth1.
Jun 17 14:48:51 server140 avahi-daemon[2239]: Leaving mDNS multicast group on interface eth1.IPv6 with address fe80::baac:6fff:fe93:213f.
Jun 17 14:48:51 server140 avahi-daemon[2239]: iface.c: interface_mdns_mcast_join() called but no local address available.
Jun 17 14:48:51 server140 avahi-daemon[2239]: Interface eth1.IPv6 no longer relevant for mDNS.
Jun 17 14:48:51 server140 kernel: bnx2: eth0: using MSIX
Jun 17 14:48:51 server140 kernel: ADDRCONF(NETDEV_UP): eth0: link is not ready
Jun 17 14:48:55 server140 avahi-daemon[2239]: New relevant interface eth0.IPv4 for mDNS.
Jun 17 14:48:55 server140 avahi-daemon[2239]: Joining mDNS multicast group on interface eth0.IPv4 with address 125.76.225.123.
Jun 17 14:48:55 server140 avahi-daemon[2239]: Registering new address record for 125.76.225.123 on eth0.
Jun 17 14:48:55 server140 kernel: bnx2: eth1: using MSIX
Jun 17 14:48:55 server140 kernel: ADDRCONF(NETDEV_UP): eth1: link is not ready
Jun 17 14:48:57 server140 kernel: bnx2: eth1 NIC Copper Link is Up, 100 Mbps full duplex
Jun 17 14:48:57 server140 kernel: ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready

上面是日志注意观察eth0，eth1是好的所以我重启了出现的日志是这样的

Jun 17 14:48:55 server140 kernel: bnx2: eth1: using MSIX
Jun 17 14:48:55 server140 kernel: ADDRCONF(NETDEV_UP): eth1: link is not ready
Jun 17 14:48:57 server140 kernel: bnx2: eth1 NIC Copper Link is Up, 100 Mbps full duplex
Jun 17 14:48:57 server140 kernel: ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready

但eth0的日志如下：
Jun 17 14:48:51 server140 kernel: ADDRCONF(NETDEV_UP): eth0: link is not ready
Jun 17 14:48:55 server140 avahi-daemon[2239]: New relevant interface eth0.IPv4 for mDNS.
Jun 17 14:48:55 server140 avahi-daemon[2239]: Joining mDNS multicast group on interface eth0.IPv4 with address 125.76.225.123.
Jun 17 14:48:55 server140 avahi-daemon[2239]: Registering new address record for 125.76.225.123 on eth0.

没有出现 link becomes ready

当插入网线，出现下面日志：
Jun 17 14:52:01 server140 kernel: bnx2: eth0 NIC Copper Link is Down
Jun 17 14:52:08 server140 kernel: bnx2: eth0 NIC Copper Link is Up, 100 Mbps full duplex
Jun 17 14:52:08 server140 kernel: bnx2: eth0 NIC Copper Link is Down
Jun 17 14:52:24 server140 kernel: bnx2: eth0 NIC Copper Link is Up, 100 Mbps full duplex
Jun 17 14:52:24 server140 kernel: bnx2: eth0 NIC Copper Link is Down
Jun 17 14:52:28 server140 kernel: bnx2: eth0 NIC Copper Link is Up, 100 Mbps full duplex
Jun 17 14:52:28 server140 kernel: bnx2: eth0 NIC Copper Link is Down
Jun 17 14:52:36 server140 kernel: bnx2: eth0 NIC Copper Link is Up, 100 Mbps full duplex
Jun 17 14:53:32 server140 avahi-daemon[2239]: Registering new address record for 125.76.225.140 on eth0.
Jun 17 14:53:37 server140 avahi-daemon[2239]: Withdrawing address record for 125.76.225.140 on eth0.
Jun 17 14:53:37 server140 avahi-daemon[2239]: Withdrawing address record for 125.76.225.123 on eth0.

过一会就出现：
Jun 17 14:53:39 server140 kernel: ADDRCONF(NETDEV_UP): eth0: link is not ready
Jun 17 14:53:41 server140 kernel: bnx2: eth0 NIC Copper Link is Up, 100 Mbps full duplex
Jun 17 14:53:41 server140 kernel: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
正常了

我很郁闷，IP地址全部配置好了，但就是不通，原来是网线连接出现问题。

总结：1.出现问题时，需要冷静。

      2.学会查看日志，从日志里分析出对你有用的东西。

      3.当你使用《经验法》解决不了时，学会《逻辑法》《辩证法》去排错。

方法总比困难多，每个人都有自己擅长的解决问题的方法，只要集思广益，方法会层出不穷。