4.29 日维修过后，有半个月了吧…拖延证有点严重。上月底一次停电，来电后，服务器网络有故障了，专门去了一趟老校区来修理。
到了机房，ifconfig 查看网络接口的状态。恩，大致是这样：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 vvl@xdlinux:~$ ifconfig docker0 Link encap:Ethernet HWaddr 02:42:1a:1b:75:06 inet addr:172.17.0.1 Bcast:0.0.0.0 Mask:255.255.0.0 inet6 addr: fe80::1/64 Scope:Link inet6 addr: fe80::42:1aff:fe1b:7506/64 Scope:Link inet6 addr: fdbd:6b69:4dc6::1/48 Scope:Global UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:162393390 errors:0 dropped:0 overruns:0 frame:0 TX packets:331323123 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:12041875764 (11.2 GiB) TX bytes:498767843534 (464.5 GiB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:2238346 errors:0 dropped:0 overruns:0 frame:0 TX packets:2238346 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:377411960 (359.9 MiB) TX bytes:377411960 (359.9 MiB)
显然网卡没启动，/etc/init.d/networking 走起。=_= 没有任何输出信息…诶，那就手动启动吧。ifconfig ethx up ~再ifconfig，大致是这样的输出：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 vvl@xdlinux:~$ ifconfig docker0 Link encap:Ethernet HWaddr 02:42:1a:1b:75:06 inet addr:172.17.0.1 Bcast:0.0.0.0 Mask:255.255.0.0 inet6 addr: fe80::1/64 Scope:Link inet6 addr: fe80::42:1aff:fe1b:7506/64 Scope:Link inet6 addr: fdbd:6b69:4dc6::1/48 Scope:Global UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:162393390 errors:0 dropped:0 overruns:0 frame:0 TX packets:331323123 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:12041875764 (11.2 GiB) TX bytes:498767843534 (464.5 GiB) eth0 Link encap:Ethernet HWaddr 48:5b:39:b8:37:0d UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:332151441 errors:0 dropped:66005 overruns:0 frame:0 TX packets:162917713 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:502086864230 (467.6 GiB) TX bytes:15667890997 (14.5 GiB) eth1 Link encap:Ethernet HWaddr 00:23:7d:6d:50:9d UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:35736452 errors:1 dropped:22061 overruns:0 frame:1 TX packets:129046572 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2719695714 (2.5 GiB) TX bytes:192402119248 (179.1 GiB) Interrupt:19 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:65536 Metric:1 RX packets:2238346 errors:0 dropped:0 overruns:0 frame:0 TX packets:2238346 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:377411960 (359.9 MiB) TX bytes:377411960 (359.9 MiB)
ps: 忽略 RX/TX bytes…不要在意细节。再说，我也不知道是不是这样的输出，我是根据ip addr看出问题的~！
1 2 3 4 5 6 7 8 2: enp3s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000 link/ether 94:de:80:af:d8:39 brd ff:ff:ff:ff:ff:ff inet 10.170.41.48/16 brd 10.170.255.255 scope global dynamic enp3s0 valid_lft 246001sec preferred_lft 246001sec inet6 2001:250:1006:dff0::1:67a2/128 scope global dynamic valid_lft 245998sec preferred_lft 159598sec inet6 fe80::13e0:ea7:7fe3:d7b3/64 scope link valid_lft forever preferred_lft forever
输出差不多是上面那样，注意__<NO-CARRIER,BROADCAST,MULTICAST,UP>__，__NO-CARRIER__嘛，物理层的问题？…（省略若干被遗忘的东西）总之，网卡插得好好的，没问题。sudo pon dsl-provider 成功拨号，手动添加IP 地址、路由，成功。此时就剩下一个问题了：/etc/init.d/networking 启动脚本怎么了？
先从自己正常工作的腾讯云上 download 下来一个，diff 二者，没问题。思考，这是怎么了呢？后来想到，ifupdown这个工具是用来管理网络接口的，是不是他们出问题了呢？尝试搜了一下这个包：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 vvl@xdlinux:~$ apt search ifupdown Sorting... Done Full Text Search... Done guessnet/stable 0.56 amd64 Guess which LAN a network device is connected to ifupdown/stable,now 0.7.53.1 amd64 [...] high level tools to configure network interfaces ifupdown-extra/stable 0.25 all Network scripts for ifupdown ifupdown-multi/stable 0.1.1 all multiple default gateway support for ifupdown ifupdown-scripts-zg2/stable 0.6-1 all Zugschlus' interface scripts for ifupdown's manual method netscript-ipfilter/stable 5.4.10 all Linux 2.6/3.x iptables management system.
哇，还真有这个包，[...]内容我忘记了，反正不是正常安装的[installed]。重新安装之，重启，搞定。
很奇怪：这个包是怎么损坏的呢？一个玄学…