After installing docker, sometimes the docker is uninstalled, and the virtual bridge is still there. At this time, the docker bridge needs to be manually uninstalled
ifconfig to view the name of the network card created by docker, which usually starts with br and docker0
Install the brctl tool
Fedora/Centos system
$ yum install -y bridge-utils
Debian/Ubuntu system
$ apt-get install -y bridge-utils
stop docker service
systemctl stop docker
Stop the docker virtual network card
ifconfig br-69ec69521ef3 down && ifconfig docker0 down
Delete virtual network card
brctl delbr br-69ec69521ef3 && brctl delbr docker0