记一次Debian无网络修复

剧情引入[/doge]

某日闲来无聊监控服务器时发现一台机子掉线了，起初以为被GFW给墙了，吓得我赶紧用ping.pe测一下，
结果全是红，我意识到可能是机子出问题了。
遂登录服务商控制面板，发现机子显示在线，使用网页VNC登录执行

ifconfig #查看网卡

我淦，我网卡呢?，怎么只剩一个loopback了

然后尝试重启机器和网络服务，发现

使用systemctl status networking查看服务状态发现缺失iptables-restore命令

???近期都没登录机子iptables咋就坏掉了

下面开始修复

设置机子进入救援模式(服务商有这个选项，如果没有就没办法了，本地虚拟机请自行百度)

救援模式有网络连接，使用ssh连接到机子

更新一下软件源并检查wget

apt-get update
apt-get install wget

挂载系统

mount /dev/vda1 /mnt #PS：你的源系统可能不是vda1,以实际为准
ls /mnt/usr/sbin|grep iptables #发现确实找不到iptables-restore

打开网站https://packages.debian.org/搜索iptables

选择需要的版本右键复制下载链接

使用wget下载到本地

cd /mnt/home/
wget http://ftp.us.debian.org/debian/pool/main/i/iptables/iptables_1.8.7-1_amd64.deb #不要无脑复制，请以实际为准

使用dpkg命令安装到指定rootfs

dpkg --root=/mnt -i iptables_1.8.7-1_amd64.deb

发现报错，用户缺失

为当前救援模式添加用户crontab

useradd crontab #请以实际为准

再次安装iptables

发现报错，缺失依赖关系

遂手动检查并下载依赖，然后再一个一个安装测试

rescue # dpkg --root=/mnt -i libc6_2.31-13+deb11u2_amd64.deb 
(Reading database ... 30993 files and directories currently installed.)
Preparing to unpack libc6_2.31-13+deb11u2_amd64.deb ...
Unpacking libc6:amd64 (2.31-13+deb11u2) over (2.31-13+deb11u2) ...
Setting up libc6:amd64 (2.31-13+deb11u2) ...
Processing triggers for libc-bin (2.31-13+deb11u2) ...
rescue # dpkg --root=/mnt -i iptables_1.8.7-1_amd64.deb 
(Reading database ... 30993 files and directories currently installed.)
Preparing to unpack iptables_1.8.7-1_amd64.deb ...
Unpacking iptables (1.8.7-1) over (1.8.7-1) ...
dpkg: dependency problems prevent configuration of iptables:
 iptables depends on libip6tc2 (= 1.8.7-1); however:
  Package libip6tc2 is not installed.
 iptables depends on libnetfilter-conntrack3 (>= 1.0.8); however:
  Package libnetfilter-conntrack3 is not installed.
 iptables depends on libnfnetlink0; however:
  Package libnfnetlink0 is not installed.

dpkg: error processing package iptables (--install):
 dependency problems - leaving unconfigured
Processing triggers for man-db (2.9.4-2) ...
Errors were encountered while processing:
 iptables
rescue # dpkg --root=/mnt -i libip6tc2_1.8.7-1_amd64.deb 
Selecting previously unselected package libip6tc2:amd64.
(Reading database ... 30993 files and directories currently installed.)
Preparing to unpack libip6tc2_1.8.7-1_amd64.deb ...
Unpacking libip6tc2:amd64 (1.8.7-1) ...
Setting up libip6tc2:amd64 (1.8.7-1) ...
Processing triggers for libc-bin (2.31-13+deb11u2) ...
rescue # dpkg --root=/mnt -i iptables_1.8.7-1_amd64.deb 
(Reading database ... 30999 files and directories currently installed.)
Preparing to unpack iptables_1.8.7-1_amd64.deb ...
Unpacking iptables (1.8.7-1) over (1.8.7-1) ...
dpkg: dependency problems prevent configuration of iptables:
 iptables depends on libnetfilter-conntrack3 (>= 1.0.8); however:
  Package libnetfilter-conntrack3 is not installed.
 iptables depends on libnfnetlink0; however:
  Package libnfnetlink0 is not installed.

dpkg: error processing package iptables (--install):
 dependency problems - leaving unconfigured
Processing triggers for man-db (2.9.4-2) ...
Errors were encountered while processing:
 iptables
rescue # wget http://ftp.us.debian.org/debian/pool/main/libn/libnetfilter-conntrack/libnetfilter-conntrack3_1.0.8-3_amd64.deb
--2022-02-09 04:53:06--  http://ftp.us.debian.org/debian/pool/main/libn/libnetfilter-conntrack/libnetfilter-conntrack3_1.0.8-3_amd64.deb
Resolving ftp.us.debian.org (ftp.us.debian.org)... 64.50.236.52, 64.50.233.100, 208.80.154.139, ...
Connecting to ftp.us.debian.org (ftp.us.debian.org)|64.50.236.52|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 40640 (40K)
Saving to: ‘libnetfilter-conntrack3_1.0.8-3_amd64.deb’

libnetfilter-conntrack3_1.0.8-3_amd64.deb  100%[=====================================================================================>]  39.69K  --

2022-02-09 04:53:06 (929 KB/s) - ‘libnetfilter-conntrack3_1.0.8-3_amd64.deb’ saved [40640/40640]

rescue # dpkg --root=/mnt -i libnetfilter-conntrack3_1.0.8-3_amd64.deb 
Selecting previously unselected package libnetfilter-conntrack3:amd64.
(Reading database ... 30999 files and directories currently installed.)
Preparing to unpack libnetfilter-conntrack3_1.0.8-3_amd64.deb ...
Unpacking libnetfilter-conntrack3:amd64 (1.0.8-3) ...
dpkg: dependency problems prevent configuration of libnetfilter-conntrack3:amd64:
 libnetfilter-conntrack3:amd64 depends on libnfnetlink0; however:
  Package libnfnetlink0 is not installed.

dpkg: error processing package libnetfilter-conntrack3:amd64 (--install):
 dependency problems - leaving unconfigured
Processing triggers for libc-bin (2.31-13+deb11u2) ...
Errors were encountered while processing:
 libnetfilter-conntrack3:amd64
rescue # wget http://ftp.us.debian.org/debian/pool/main/libn/libnfnetlink/libnfnetlink0_1.0.1-3+b1_amd64.deb
--2022-02-09 04:53:36--  http://ftp.us.debian.org/debian/pool/main/libn/libnfnetlink/libnfnetlink0_1.0.1-3+b1_amd64.deb
Resolving ftp.us.debian.org (ftp.us.debian.org)... 64.50.236.52, 208.80.154.139, 64.50.233.100, ...
Connecting to ftp.us.debian.org (ftp.us.debian.org)|64.50.236.52|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 13908 (14K)
Saving to: ‘libnfnetlink0_1.0.1-3+b1_amd64.deb’

libnfnetlink0_1.0.1-3+b1_amd64.deb         100%[=====================================================================================>]  13.58K  --

2022-02-09 04:53:36 (86.1 MB/s) - ‘libnfnetlink0_1.0.1-3+b1_amd64.deb’ saved [13908/13908]

rescue # dpkg --root=/mnt -i libnfnetlink0_1.0.1-3+b1_amd64.deb 
Selecting previously unselected package libnfnetlink0:amd64.
(Reading database ... 31004 files and directories currently installed.)
Preparing to unpack libnfnetlink0_1.0.1-3+b1_amd64.deb ...
Unpacking libnfnetlink0:amd64 (1.0.1-3+b1) ...
Setting up libnfnetlink0:amd64 (1.0.1-3+b1) ...
Processing triggers for libc-bin (2.31-13+deb11u2) ...
rescue # dpkg --root=/mnt -i libnetfilter-conntrack3_1.0.8-3_amd64.deb 
(Reading database ... 31010 files and directories currently installed.)
Preparing to unpack libnetfilter-conntrack3_1.0.8-3_amd64.deb ...
Unpacking libnetfilter-conntrack3:amd64 (1.0.8-3) over (1.0.8-3) ...
Setting up libnetfilter-conntrack3:amd64 (1.0.8-3) ...
Processing triggers for libc-bin (2.31-13+deb11u2) ...
rescue # dpkg --root=/mnt -i iptables_1.8.7-1_amd64.deb 
(Reading database ... 31010 files and directories currently installed.)
Preparing to unpack iptables_1.8.7-1_amd64.deb ...
Unpacking iptables (1.8.7-1) over (1.8.7-1) ...
Setting up iptables (1.8.7-1) ...
update-alternatives: using /usr/sbin/iptables-legacy to provide /usr/sbin/iptables (iptables) in auto mode
update-alternatives: using /usr/sbin/ip6tables-legacy to provide /usr/sbin/ip6tables (ip6tables) in auto mode
update-alternatives: using /usr/sbin/iptables-nft to provide /usr/sbin/iptables (iptables) in auto mode
update-alternatives: using /usr/sbin/ip6tables-nft to provide /usr/sbin/ip6tables (ip6tables) in auto mode
update-alternatives: using /usr/sbin/arptables-nft to provide /usr/sbin/arptables (arptables) in auto mode
update-alternatives: using /usr/sbin/ebtables-nft to provide /usr/sbin/ebtables (ebtables) in auto mode
Processing triggers for man-db (2.9.4-2) ...

成功安装iptables 使用命令检查是否存在iptables-restore

rescue # pwd
/mnt/home
rescue # ls /mnt/usr/sbin/|grep iptables
iptables
iptables-apply
iptables-legacy
iptables-legacy-restore
iptables-legacy-save
iptables-nft
iptables-nft-restore
iptables-nft-save
iptables-restore
iptables-restore-translate
iptables-save
iptables-translate

OK!退出救援模式重启机子，并使用WebVNC连接