1. #查看看容器内部的网络地址 ip addr，发现容器启动的时候会得到一个地址eth0@if117 172.17.0.2就是它当前的ip地址
    2. [root@iZbp10cl07degikl645xkmZ ~]# docker exec -it kaoqin ip addr
    3. 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1000
    4.     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    5.     inet 127.0.0.1/8 scope host lo
    6.        valid_lft forever preferred_lft forever
    7. 116: eth0@if117: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP 
    8.     link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff
    9.     inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0
    10.        valid_lft forever preferred_lft forever
    11. [root@iZbp10cl07degikl645xkmZ ~]#

    容器与容器之间是可以相互ping通的 ，宿主机可以看作为路由器作为桥接。