与网络相关的一切似乎都已关闭 Ubuntu 16.04答案

【问题标题】：Everything network related seems to be down Ubuntu 16.04与网络相关的一切似乎都已关闭 Ubuntu 16.04
【发布时间】：2018-09-20 19:15:14
【问题描述】：

昨天我正在使用 PHP 和 MySQL 在我的服务器上开发一个仪表板。我今天进来完成所说的仪表板并得到以下输出：

git clone https://github.com/tbg/tcd
Cloning into 'tcd'...
fatal: unable to access 'https://github.com/tbg/tcd/': Could not resolve host: github.com

深入研究这个问题，我发现apt-get 也遇到了以下问题：

apt-get update
Err:1 http://ppa.launchpad.net/certbot/certbot/ubuntu xenial InRelease
  Could not resolve 'ppa.launchpad.net'
Err:2 http://security.ubuntu.com/ubuntu xenial-security InRelease                                            
  Could not resolve 'security.ubuntu.com'
Err:3 http://ppa.launchpad.net/ondrej/php/ubuntu xenial InRelease                                            
  Could not resolve 'ppa.launchpad.net'
Err:4 http://us.archive.ubuntu.com/ubuntu xenial InRelease               
  Could not resolve 'us.archive.ubuntu.com'
Err:5 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease       
  Could not resolve 'us.archive.ubuntu.com'
Err:6 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease
  Could not resolve 'us.archive.ubuntu.com'
Err:7 https://download.docker.com/linux/ubuntu xenial InRelease
  Could not resolve host: download.docker.com
Err:8 https://deb.nodesource.com/node_8.x xenial InRelease
  Could not resolve host: deb.nodesource.com
Err:9 http://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/3.2 InRelease
  Could not resolve 'repo.mongodb.org'
Reading package lists... Done      
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/xenial/InRelease  Could not resolve 'us.archive.ubuntu.com'
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/xenial-updates/InRelease  Could not resolve 'us.archive.ubuntu.com'
W: Failed to fetch http://us.archive.ubuntu.com/ubuntu/dists/xenial-backports/InRelease  Could not resolve 'us.archive.ubuntu.com'
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/xenial-security/InRelease  Could not resolve 'security.ubuntu.com'
W: Failed to fetch https://download.docker.com/linux/ubuntu/dists/xenial/InRelease  Could not resolve host: download.docker.com
W: Failed to fetch http://ppa.launchpad.net/certbot/certbot/ubuntu/dists/xenial/InRelease  Could not resolve 'ppa.launchpad.net'
W: Failed to fetch http://repo.mongodb.org/apt/ubuntu/dists/xenial/mongodb-org/3.2/InRelease  Could not resolve 'repo.mongodb.org'
W: Failed to fetch https://deb.nodesource.com/node_8.x/dists/xenial/InRelease  Could not resolve host: deb.nodesource.com
W: Failed to fetch http://ppa.launchpad.net/ondrej/php/ubuntu/dists/xenial/InRelease  Could not resolve 'ppa.launchpad.net'
W: Some index files failed to download. They have been ignored, or old ones used instead.

尝试解析 apt-get 主机我得到以下信息：

host -v us.archive.ubuntu.com
Trying "us.archive.ubuntu.com"
;; connection timed out; no servers could be reached

我认为这将是一个 DNS 问题，所以我检查了我的 resolv.conf 文件并看到以下输出：

cat /etc/resolv.conf
cat: /etc/resolv.conf: No such file or directory

所以现在我迷路了，这是怎么回事？如何才能成功解决这个问题？

编辑：

ifconfig 表明我有一个预期的 IP 地址：

eno1      Link encap:Ethernet  HWaddr d0:94:67:41:8b:b3  
          inet addr:10.1.1.78  Bcast:10.1.1.255  Mask:255.255.255.0
          inet6 addr: fe80::d294:66ff:fe51:5bb3/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:13800 errors:0 dropped:1 overruns:0 frame:0
          TX packets:2420 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:4767680 (4.7 MB)  TX bytes:559473 (559.4 KB)
          Interrupt:17

【问题讨论】：

我遇到了完全相同的问题。看起来你也找不到解决方案:(

标签： networking ubuntu-16.04

【解决方案1】：

我在 Ubuntu 上遇到了同样的问题：

运行：

systemctl enable systemd-resolved --now
ln -sf /run/systemd/resolve/resolv.conf /etc/resolv.conf
nano /etc/systemd/resolved.conf

并添加相关的 DNS，例如： DNS=8.8.8.8

【讨论】：

【解决方案2】：

我能够通过以下方式完全解决此问题：

$ sudo dpkg-reconfigure resolvconf
$ sudo cat<<EOF > /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 8.8.8.8
nameserver 8.8.4.4
EOF
$ /etc/init.d/networking restart
$ sudo ifdown <INTERFACE>
$ sudo ifup <INTERFACE>

【讨论】：