1.查看网卡名。

root@debian:~# ip addr

 可以看出只有一块网卡，名为ens33。

root@debian:~# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
    link/ether 00:0c:29:cd:3f:b8 brd ff:ff:ff:ff:ff:ff
    inet 192.168.20.132/24 brd 192.168.20.255 scope global dynamic ens33
       valid_lft 1751sec preferred_lft 1751sec
    inet6 fe80::20c:29ff:fecd:3fb8/64 scope link 
       valid_lft forever preferred_lft forever

2.修改网卡配置文件。

root@debian:~# vi /etc/network/interfaces      

3.dhcp配置示例

 4.静态配置方式。（多块网卡可以写多个）

# This file describes the network interfaces available on your sys
# This file describes the network interfaces available on your sys
tem
# and how to activate them. For more information, see interfaces(5
).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
allow-hotplug ens33                            #ens33网卡名
iface ens33 inet static                        #静态地址
address 192.168.20.100/24                      #ip地址/掩码
gateway 192.168.20.2                           #网关
dns-nameservers 8.8.8.8                        #dns

 5.保存退出  Esc+:wq

6. 修改DNS配置文件

root@debian:~# vim /etc/resolv.conf 

7.重启Debian刷新网卡。

root@debian:~# reboot 

8.验证  

root@debian:~# ip addr