Ubuntu中创建虚拟网卡验证客户端是否真的通过VPN

参考： https://blog.csdn.net/zgf19930504/article/details/51955067

1 先使用ifconfig查看网卡名称

$ ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.3.39  netmask 255.255.255.0  broadcast 192.168.3.255
        inet6 fe80::279b:4479:ea46:ae99  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:ee:4b:bc  txqueuelen 1000  (Ethernet)
        RX packets 44187  bytes 21079541 (21.0 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 29266  bytes 9993375 (9.9 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0


lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 810  bytes 71857 (71.8 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 810  bytes 71857 (71.8 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

我的网卡名称为ens33.

2 修改文件添加网卡

修改文件/etc/network/interfaces，添加网卡，网卡名为：原来网卡（ens33）:1，可以创建多个，修改:后面的数字即可。

$ sudo vim /etc/network/interfaces

原始内容为：

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

改为:

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

auto ens33:1
iface ens33:1 inet static
address 123.1.0.123
netmask 255.255.255.0

3 使用ifconfig查看结果

$ sudo /etc/init.d/networking restart
$ ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.3.39  netmask 255.255.255.0  broadcast 192.168.3.255
        inet6 fe80::279b:4479:ea46:ae99  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:ee:4b:bc  txqueuelen 1000  (Ethernet)
        RX packets 44442  bytes 21113893 (21.1 MB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 29484  bytes 10015338 (10.0 MB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0


ens33:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 123.1.0.123  netmask 255.255.255.0  broadcast 123.1.0.255
        ether 00:0c:29:ee:4b:bc  txqueuelen 1000  (Ethernet)


lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 870  bytes 76225 (76.2 KB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 870  bytes 76225 (76.2 KB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

4 访问123.1.0.123，查看是否可以访问

先用Ubuntu访问http://123.1.0.123，确定是可以访问到内容的

Android设备未连接VPN的情况下访问http://123.1.0.123，访问不通

Android设备连接VPN后访问http://123.1.0.123，可以成功访问

PS：在这里我是先安装了apache（sudo apt-get install apache2 apache2-doc），访问http://123.1.0.123和访问http://127.0.0.1的效果相同。