Introduction to Linux Network Namespaces

An introduction to Linux network namespaces.
Twitter: @davidmahler
LinkedIn: https://www.linkedin.com/in/davidmahler

This video is lab style in that you can follow along on your own system or just watch. I walk through 2 examples mimicking how Mininet emulates hosts and how OpenStack provides DHCP services (they both use network namespaces)

links:
My Intro to OVS video - https://youtu.be/rYW7kQRyUvA
My Intro to Mininet video - https://youtu.be/jmlgXaocwiE

references
http://man7.org/linux/man-pages/man8/ip-netns.8.html
http://openvswitch.org
http://mininet.org
Bob Lantz, Brian O'Connor Mininet presentation - https://youtu.be/90fBCO1MMTA
http://docs.openstack.org (networking documentation)
http://www.opencloudblog.com (linux networking entries)

Commands used:
Checking out L2/L3:
ip link
ip address
ip route

add an ip address to an interface:
ip address add (ip/mask length) dev (intf name)

turn an interface up
ip link set dev (intf name) up
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Add network namespace:
ip netns add (name)

Delete network namespace:
ip netns del (name)

Execute a command in a specific namespace:
ip netns exec (name) (command to execute)

Move a port to a namespace:
ip link set (intf name) netns (net namespace name)

What net namespace is a process ID running in?
ip netns identify (pid)
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OVS
add a vSwitch:
ovs-vsctl add-br (name)

add an interface to OVS instance:
ovs-vsctl add-port (OVS name) (intf name)

Create a veth pair:
ip link add (end1 name) type veth peer name (end2 name)

Place a port in a vlan:
ovs-vsctl set port (intf name) tag=(vlan number)

Make a port type internal:
ovs-vsctl set port (intf name) type=internal
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