修改Ubuntu20.04 、Centos7.6的DNS_ubuntu20.04配置dns

1.Ubuntu20.04 系统中设置dns并生效

在Ubuntu20.04的文件/etc/resolv.conf只能查看，不能修改

方法一：修改/etc/systemd/resolved.conf 文件

vim /etc/systemd/resolved.conf

systemctl restart systemd-resolved
systemctl enable systemd-resolved
mv /etc/resolv.conf  /etc/resolv.conf.bak
ln -s /run/systemd/resolve/resolv.conf /etc/

cat /etc/resolv.conf    #查看dns文件

方法二：修改/etc/netplan/00-installer-config.yaml文件

vim /etc/netplan/00-installer-config.yaml

netplan apply  #生效

cat /etc/resolv.conf    #查看dns文件

2.Centos7.6 系统中设置dns并生效

在Centos7.6的文件/etc/resolv.con可以修改

vim /etc/resolv.conf 

systemctl restart NetworkManager #生效

cat /etc/resolv.conf    #查看dns文件