centos及Ubuntu服务器修改DNS配置

公司办公网络网段通过DHCP自动分配IP，服务器网段是手动配置的固定IP，nameserver统一指向服务器网段的网关，最近由于公司路由器服务器网段DNS解析问题，不得不手动配置服务器的dns，以此记录下。

centos修改dns：

1：找到网络配置文件

cd /etc/sysconfig/network-scripts/

ll

-rw-r--r--. 1 root root   366 Apr 17  2023 ifcfg-eth0
-rw-r--r--. 1 root root   254 May 22  2020 ifcfg-lo
lrwxrwxrwx. 1 root root    24 Apr 17  2023 ifdown -> ../../../usr/sbin/ifdown
-rwxr-xr-x. 1 root root   654 May 22  2020 ifdown-bnep
-rwxr-xr-x. 1 root root  6532 May 22  2020 ifdown-eth
-rwxr-xr-x. 1 root root   781 May 22  2020 ifdown-ippp
-rwxr-xr-x. 1 root root  4540 May 22  2020 ifdown-ipv6
lrwxrwxrwx. 1 root root    11 Apr 17  2023 ifdown-isdn -> ifdown-ippp
-rwxr-xr-x. 1 root root  2130 May 22  2020 ifdown-post
-rwxr-xr-x. 1 root root  1068 May 22  2020 ifdown-ppp
-rwxr-xr-x. 1 root root   870 May 22  2020 ifdown-routes
-rwxr-xr-x. 1 root root  1456 May 22  2020 ifdown-sit
-rwxr-xr-x. 1 root root  1621 Dec  9  2018 ifdown-Team
-rwxr-xr-x. 1 root root  1556 Dec  9  2018 ifdown-TeamPort
-rwxr-xr-x. 1 root root  1462 May 22  2020 ifdown-tunnel
lrwxrwxrwx. 1 root root    22 Apr 17  2023 ifup -> ../../../usr/sbin/ifup
-rwxr-xr-x. 1 root root 12415 May 22  2020 ifup-aliases
-rwxr-xr-x. 1 root root   910 May 22  2020 ifup-bnep
-rwxr-xr-x. 1 root root 13758 May 22  2020 ifup-eth
-rwxr-xr-x. 1 root root 12075 May 22  2020 ifup-ippp
-rwxr-xr-x. 1 root root 11893 May 22  2020 ifup-ipv6
lrwxrwxrwx. 1 root root     9 Apr 17  2023 ifup-isdn -> ifup-ippp
-rwxr-xr-x. 1 root root   650 May 22  2020 ifup-plip
-rwxr-xr-x. 1 root root  1064 May 22  2020 ifup-plusb
-rwxr-xr-x. 1 root root  4997 May 22  2020 ifup-post
-rwxr-xr-x. 1 root root  4154 May 22  2020 ifup-ppp
-rwxr-xr-x. 1 root root  2001 May 22  2020 ifup-routes
-rwxr-xr-x. 1 root root  3303 May 22  2020 ifup-sit
-rwxr-xr-x. 1 root root  1755 Dec  9  2018 ifup-Team
-rwxr-xr-x. 1 root root  1876 Dec  9  2018 ifup-TeamPort
-rwxr-xr-x. 1 root root  2780 May 22  2020 ifup-tunnel
-rwxr-xr-x. 1 root root  1836 May 22  2020 ifup-wireless
-rwxr-xr-x. 1 root root  5419 May 22  2020 init.ipv6-global
-rw-r--r--. 1 root root 20678 May 22  2020 network-functions
-rw-r--r--. 1 root root 30988 May 22  2020 network-functions-ipv6

2：找到带网卡名的配置文件并修改配置文件

vi ifcfg-eth0


DEVICE=eth0
ONBOOT=yes
IPADDR=********
NETMASK=******
GATEWAY=******

#手动改成自己需要的dns
DNS1=114.114.114.114

3：重启网络

systemctl restart network

Ubuntu服务器修改dns:

1：Ubuntu是通过netplan管理的，还是找到网络配置文件

cd  /etc/netplan
ll

-rw-r--r--  1 root root  585 Nov 18 03:14 50-cloud-init.yaml

vim 50-cloud-init.yaml

2：修改配置文件，如果多网卡机器找对自己的网卡名，然后修改对应的nameserver下的addresses为自己想要的dns即可

network:
    ethernets:
        enp5s0:
            addresses:
            - 192.168.199.177/24
            gateway4: 192.168.199.1
            nameservers:
                addresses: [114.114.114.114]
                search:
                - 192.168.199.1
    version: 2

3：应用配置到网络

netplan apply