$ sudo ip netns exec ns2 ip link show | grep "link/ether"
link/ether 00:00:5e:00:53:02 brd ff:ff:ff:ff:ff:ff link-netns ns1
</pre>
*別ターミナルから、パケットキャプチャ準備
<pre>
$ sudo ip netns exec ns1 tcpdump -tnel -i ns1-veth0 icmp
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on ns1-veth0, link-type EN10MB (Ethernet), capture size 262144 bytes
</pre>
*ns1 から ns2 へping
<pre>
</pre>