使用wsl中的debian10更新时，出现如下错误：
admin@DESKTOP:~$ sudo apt update Err:1 http://deb.debian.org/debian buster InRelease Could not connect to debian.map.fastlydns.net:80 (127.167.1.230). - connect (111: Connection refused) Cannot initiate the connection to debian.map.fastlydns.net:80 (fd00:696e:6974:6578::4f:1e7). - connect (101: Network is unreachable) Could not connect to deb.debian.org:80 (127.167.1.232). - connect (111: Connection refused) Cannot initiate the connection to deb.debian.org:80 (fd00:696e:6974:6578::4f:1e9). - connect (101: Network is unreachable) Err:2 http://deb.debian.org/debian buster-updates InRelease Cannot initiate the connection to deb.debian.org:80 (fd00:696e:6974:6578::4f:1e9). - connect (101: Network is unreachable) Err:3 http://ftp.debian.org/debian buster-backports InRelease Could not connect to debian.map.fastlydns.net:80 (127.167.1.230). - connect (111: Connection refused) Cannot initiate the connection to debian.map.fastlydns.net:80 (fd00:696e:6974:6578::4f:1e7). - connect (101: Network is unreachable) Could not connect to ftp.debian.org:80 (127.167.2.112). - connect (111: Connection refused) Cannot initiate the connection # This file was automatically generated by WSL. To stop automatic generation of this file, add the following entry to /eto ftp.debian.org:80 (fd00:696e:6974:6578::4f:271). - connect (101: Network is unreachable) Err:4 http://security.debian.org/debian-security buster/updates InRelease Could not connect to debian.map.fastlydns.net:80 (127.167.1.230). - connect (111: Connection refused) Cannot initiate the connection to debian.map.fastlydns.net:80 (fd00:696e:6974:6578::4f:1e7). - connect (101: Network is unreachable) Could not connect to security.debian.org:80 (127.167.1.234). - connect (111: Connection refused) Cannot initiate the connection to security.debian.org:80 (fd00:696e:6974:6578::4f:1eb). - connect (101: Network is unreachable) Reading package lists... Done Building dependency tree Reading state information... Done All packages are up to date. W: Failed to fetch http://deb.debian.org/debian/dists/buster/InRelease Could not connect to debian.map.fastlydns.net:80 (127.167.1.230). - connect (111: Connection refused) Cannot initiate the connection to debian.map.fastlydns.net:80 (fd00:696e:6974:6578::4f:1e7). - connect (101: Network is unreachable) Could not connect to deb.debian.org:80 (127.167.1.232). - connect (111: Connection refused) Cannot initiate the connection to deb.debian.org:80 (fd00:696e:6974:6578::4f:1e9). - connect (101: Network is unreachable) W: Failed to fetch http://deb.debian.org/debian/dists/buster-updates/InRelease Cannot initiate the connection to deb.debian.org:80 (fd00:696e:6974:6578::4f:1e9). - connect (101: Network is unreachable) W: Failed to fetch http://security.debian.org/debian-security/dists/buster/updates/InRelease Could not connect to debian.map.fastlydns.net:80 (127.167.1.230). - connect (111: Connection refused) Cannot initiate the connection to debian.map.fastlydns.net:80 (fd00:696e:6974:6578::4f:1e7). - connect (101: Network is unreachable) Could not connect to security.debian.org:80 (127.167.1.234). - connect (111: Connection refused) Cannot initiate the connection to security.debian.org:80 (fd00:696e:6974:6578::4f:1eb). - connect (101: Network is unreachable) W: Failed to fetch http://ftp.debian.org/debian/dists/buster-backports/InRelease Could not connect to debian.map.fastlydns.net:80 (127.167.1.230). - connect (111: Connection refused) Cannot initiate the connection to debian.map.fastlydns.net:80 (fd00:696e:6974:6578::4f:1e7). - connect (101: Network is unreachable) Could not connect to ftp.debian.org:80 (127.167.2.112). - connect (111: Connection refused) Cannot initiate the connection to ftp.debian.org:80 (fd00:696e:6974:6578::4f:271). - connect (101: Network is unreachable) W: Some index files failed to download. They have been ignored, or old ones used instead.
经过一番查询和乱搞下，发现修改dns服务器后就好了
sudo vi /etc/resolv.conf
把nameserver换成 8.8.8.8 和 8.8.4.4
在重新启动一下网络：
sudo /etc/init.d/networking restart
在更新就没有错误了。