what is the use of HOST and NONE network in docker?

Question

Trying to understand the docker networks, Docker creates the following networks automatically:

# docker network ls 
NETWORK ID          NAME                D         


        

Answer 1

Suppose your docker image support ifconfig, image name is "ubuntu/net"

Then, run docker for host & none:

sudo docker run -it --network=host ubuntu/net
root@localhost:/# ifconfig
     docker0   Link encap:Ethernet  HWaddr xxxxxxxxxxxxx
               inet addr:x.x.x.x  Bcast:0.0.0.0  Mask:255.255.0.0
     eth0      Link encap:Ethernet  HWaddr xxxxxxxxxxxx
               inet addr:y.y.y.y  Bcast:  Mask:255.255.254.0


sudo docker run -it --network=none ubuntu/net
root@localhost:/# ifconfig
     lo        Link encap:Local Loopback
               inet addr:127.0.0.1  Mask:255.0.0.0