当时我正在 linode 服务器上处理一个网站，突然它离线了。尝试通过网络连接时，我收到：
This site can’t be reached
xxxxx.com took too long to respond.
Search Google for xxxxx
ERR_CONNECTION_TIMED_OUT
这是从每个浏览器（包括隐身模式）得到的。我也无法通过 SSH 连接。此外，PING 也会导致超时。来自 Linode 提供商：系统状态为启动，我可以通过 Web 界面登录。
在系统本身上：
skunkworks:~$ networkctl list
WARNING: systemd-networkd is not running, output will be incomplete.
IDX LINK TYPE OPERATIONAL SETUP
1 lo loopback n/a unmanaged
2 dummy0 ether n/a unmanaged
3 eth0 ether n/a unmanaged
4 teql0 void n/a unmanaged
5 tunl0 tunnel n/a unmanaged
6 gre0 ipgre n/a unmanaged
7 gretap0 ether n/a unmanaged
8 erspan0 ether n/a unmanaged
9 ip_vti0 tunnel n/a unmanaged
10 ip6_vti0 tunnel6 n/a unmanaged
11 sit0 sit n/a unmanaged
12 ip6tnl0 tunnel6 n/a unmanaged
13 ip6gre0 n/a n/a unmanaged
14 docker0 ether n/a unmanaged
14 links listed.
@skunkworks:~$
我看到了！所以我尝试：
@skunkworks:~$ sudo systemctl restart systemd-networkd
@skunkworks:~$ networkctl list
IDX LINK TYPE OPERATIONAL SETUP
1 lo loopback carrier unmanaged
2 dummy0 ether off unmanaged
3 eth0 ether off unmanaged
4 teql0 void off unmanaged
5 tunl0 tunnel off unmanaged
6 gre0 ipgre off unmanaged
7 gretap0 ether off unmanaged
8 erspan0 ether off unmanaged
9 ip_vti0 tunnel off unmanaged
10 ip6_vti0 tunnel6 off unmanaged
11 sit0 sit off unmanaged
12 ip6tnl0 tunnel6 off unmanaged
13 ip6gre0 n/a off unmanaged
14 docker0 ether no-carrier unmanaged
14 links listed.
稍好一点，但仍然没有网站或 SSH！发生了什么事？有什么办法可以修复这个问题吗？
答案1
它可能已恢复你的防火墙设置。检查一下：
/sbin/iptables -t filter -L -n