network name space in linux

gistfile1.txt

network name space in linux.
create two network name spaces each having ip of 10.0.0.1 and 10.0.0.2 and ping test
configuration
host:s1-eth <-----> ns1:h1-eth
host:s2-eth <-----> ns2:h2-eth

1. create network name space
ip netns add ns1
ip netns add ns2

2. make virtual network device pair
ip link add s1-eth type veth peer name h1-eth 
ip link add s2-eth type veth peer name h2-eth 

3. associate virtual device with name space
ip link set h1-eth netns ns1
ip link set h2-eth netns ns2

4. set up lo(local loop) in name space 
ip netns exec ns1 ifconfig lo up
ip netns exec ns2 ifconfig lo up

5. assign ip in name space
ip netns exec ns1 ifconfig h1-eth 10.0.0.1/24 up
ip netns exec ns2 ifconfig h2-eth 10.0.0.2/24 up

6. make virtual interface up in host
ifconfig s1-eth up
ifconfig s2-eth up

7. make bridge device and associate virtual device with bridge device
brctl addbr br0
brctl addif br0 s1-eth 
brctl addif br0 s2-eth 

8. make bridge device up
ip link set br0 up 

9. test
ip netns exec ns1 ping 10.0.0.2
ip netns exec ns1 ping 10.0.0.1
ip netns exec ns2 ping 10.0.0.1
ip netns show
ip netns list

10. clean up
ip netns delete ns1
ip netns delete ns2
brctl delbr br0
ifconfig br0 down
brctl delbr br0
brctl show