Ubuntu 18.04 上的 aws ec2 上的实例设置问题答案

【问题标题】：Problem with instance setup on aws ec2 on Ubuntu 18.04Ubuntu 18.04 上的 aws ec2 上的实例设置问题
【发布时间】：2021-12-01 19:16:42
【问题描述】：

在 aws ec2 上创建了一个实例，并且在初始设置之后一切正常。但过了一段时间（大约第二天），服务器似乎失去了与互联网的连接。我可以连接到它，但我无法下载任何数据包。我也无法执行任何 curl 请求。只有创建服务器映像然后创建新配置才能解决问题，但第二天问题又出现了。知道如何解决这个问题吗？

创建实例时，网络设置被选为标准。 Ubuntu 18.04

示例输出：

apt update
Err:1 http://security.ubuntu.com/ubuntu bionic-security InRelease                                                           
  Cannot initiate the connection to security.ubuntu.com:80 (2001:67c:1562::18). - connect (101: Network is unreachable) Cannot initiate the connection to security.ubuntu.com:80 (2001:67c:1562::15). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (91.189.91.38), connection timed out Could not connect to security.ubuntu.com:80 (91.189.91.39), connection timed out
Err:2 http://eu-west-2.ec2.archive.ubuntu.com/ubuntu bionic InRelease                                                      
  Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (54.229.225.193), connection timed out Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (54.246.214.20), connection timed out Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (34.253.229.19), connection timed out Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (34.241.117.189), connection timed out Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (54.229.116.227), connection timed out Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (34.253.189.82), connection timed out
Err:3 http://eu-west-2.ec2.archive.ubuntu.com/ubuntu bionic-updates InRelease
  Unable to connect to eu-west-2.ec2.archive.ubuntu.com:http:
Err:4 http://eu-west-2.ec2.archive.ubuntu.com/ubuntu bionic-backports InRelease
  Unable to connect to eu-west-2.ec2.archive.ubuntu.com:http:
Reading package lists... Done
Building dependency tree       
Reading state information... Done
35 packages can be upgraded. Run 'apt list --upgradable' to see them.
W: Failed to fetch http://eu-west-2.ec2.archive.ubuntu.com/ubuntu/dists/bionic/InRelease  Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (54.229.225.193), connection timed out Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (54.246.214.20), connection timed out Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (34.253.229.19), connection timed out Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (34.241.117.189), connection timed out Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (54.229.116.227), connection timed out Could not connect to eu-west-2.ec2.archive.ubuntu.com:80 (34.253.189.82), connection timed out
W: Failed to fetch http://eu-west-2.ec2.archive.ubuntu.com/ubuntu/dists/bionic-updates/InRelease  Unable to connect to eu-west-2.ec2.archive.ubuntu.com:http:
W: Failed to fetch http://eu-west-2.ec2.archive.ubuntu.com/ubuntu/dists/bionic-backports/InRelease  Unable to connect to eu-west-2.ec2.archive.ubuntu.com:http:
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/bionic-security/InRelease  Cannot initiate the connection to security.ubuntu.com:80 (2001:67c:1562::18). - connect (101: Network is unreachable) Cannot initiate the connection to security.ubuntu.com:80 (2001:67c:1562::15). - connect (101: Network is unreachable) Could not connect to security.ubuntu.com:80 (91.189.91.38), connection timed out Could not connect to security.ubuntu.com:80 (91.189.91.39), connection timed out
W: Some index files failed to download. They have been ignored, or old ones used instead.

【问题讨论】：

标签： amazon-web-services ubuntu amazon-ec2 server instance

【解决方案1】：

该错误也可能与 DNS 有关，而与 Internet 连接无关。既然你是通过 SSH 连接到虚拟机的，那么虚拟机就可以上网了吗？

我会更改 resolv.conf 中的 DNS 服务器。这样的事情会做：

echo > /etc/resolv.conf <<EOF
nameserver 1.0.0.1
nameserver 1.1.1.1
EOF

然后再试一次，看看它是否有效。

【讨论】：