通过创建2个网络命名空间和2个虚拟网卡，使2个虚拟网卡互通

+----------------------------------------------------------------+
|                                                                |
|       +------------------------------------------------+       |
|       |             Newwork Protocol Stack             |       |
|       +------------------------------------------------+       |
|              ↑               ↑               ↑                 |
|..............|...............|...............|.................|
|              ↓               ↓               ↓                 |
|        +----------+    +-----------+   +-----------+           |
|        |   eth0   |    |   veth0   |   |   veth1   |           |
|        +----------+    +-----------+   +-----------+           |
|192.168.1.2  ↑                ↑               ↑                 |
|              |               +---------------+                 |
|              |            10.0.0.100     10.0.0.200            |
+--------------|-------------------------------------------------+
               ↓
         Physical Network

创建2个虚拟网络空间

ip netns add ns0
ip netns add ns1
ll /var/run/netns

创建2个虚拟网卡

ip link add veth0 type veth peer name veth1
ip link set veth0 netns ns0
ip link set veth1 netns ns1
ip netns exec ns0 ifconfig -a

添加ip地址

ip netns exec ns0 ifconfig veth0 10.0.0.100/24 up
ip netns exec ns1 ifconfig veth1 10.0.0.200/24 up
ip netns exec ns1 ifconfig -a

测试

ip netns exec ns0 ping 10.0.0.200 -c 10