The maximum transmission unit (MTU) defines the maximum size of IP packets sent over a network. Similar to physical networks, neutron contains a variety of layer-2 and layer-3 components that include MTU parameters. Improperly configuring neutron MTU parameters or options that impact MTU parameters can degrade network performance or cause packet loss in obscure places. We plan to cover the following topics:
- Introduction to MTU: What is it and why does it matter? What is path MTU discovery?
- Example of valid and invalid MTU configurations on a physical network.
- Relate physical networks to virtual networks.
- Discuss neutron MTU problems using both the Linux bridge and Open vSwitch agents on physical networks with 1500 and 9000 byte MTUs.
- Discuss our solution to these problems.
Operators learn about MTU, impacts of improper MTU parameters on both physical and virtual networks, neutron MTU problems, and how to properly configure neutron MTU in various environments.