$ sudo ip netns exec bridge ip link set ns2-br0 master br0
$ sudo ip netns exec bridge ip link set ns3-br0 master br0
</pre>
*ping : ns1 -> ns2
<pre>
$ sudo ip netns exec ns1 ping -c 3 192.0.2.2
PING 192.0.2.2 (192.0.2.2) 56(84) bytes of data.
64 bytes from 192.0.2.2: icmp_seq=1 ttl=64 time=0.496 ms
64 bytes from 192.0.2.2: icmp_seq=2 ttl=64 time=0.139 ms
64 bytes from 192.0.2.2: icmp_seq=3 ttl=64 time=0.141 ms
--- 192.0.2.2 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2034ms
rtt min/avg/max/mdev = 0.139/0.258/0.496/0.167 ms
</pre>