ubuntu20.04，容器以桥接模式运行的，可以ping通外网以及apt源地址，但是运行apt update出错

root@de0d656105ba:/# apt update
Err:1 http://security.ubuntu.com/ubuntu focal-security InRelease                        
  Connection failed [IP: 91.189.91.38 80]
Err:2 http://archive.ubuntu.com/ubuntu focal InRelease
  Connection failed [IP: 91.189.88.142 80]
Err:3 http://archive.ubuntu.com/ubuntu focal-updates InRelease
  Connection failed [IP: 91.189.88.142 80]