Namespace-Magic

• How detect from inside the namespace

* one way seems to look interface. inside namespace "eth1@if107" kvm "eth0:"

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
    link/ether 52:54:00:9e:81:71 brd ff:ff:ff:ff:ff:ff
</rep>


* How find veth's peer inside namespace from a host : link-netns

<pre>
on the host ip link output:

107: hweste164512@if106: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master brswan12-64512 state UP mode DEFAULT group default qlen 1000
    link/ether 4a:34:cd:0e:0c:13 brd ff:ff:ff:ff:ff:ff link-netns west-ikev2-03-basic-rawrsa

from inside the name space

106: eth1@if107: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
    link/ether 02:10:c8:8e:d2:7e brd ff:ff:ff:ff:ff:ff link-netnsid 0

from the host you get the name space name: "link-netns west-ikev2-03-basic-rawrsa" 
for exaactly which interface from "ip link" you see "106: eth1@if107",  "107: hweste164512@if106"