---
prelude: >
    Properly calculate overlay (tunnel) protocol overhead for
    environments using IPv4 or IPv6 endpoints. The ML2 plug-in
    configuration file contains a new configuration option,
    'overlay_ip_version', in the '[ml2]' section that indicates
    the IP version of all overlay network endpoints. Use '4' for
    IPv4 and '6' for IPv6. Defaults to '4'. Additionally, all
    layer-2 agents must use the same IP version for endpoints.
upgrade:
  - Define the 'overlay_ip_version' option and value
    appropriate for the environment. Only required if not
    using the Default of '4'.
other:
  - The value of the 'overlay_ip_version' option adds either
    20 bytes for IPv4 or 40 bytes for IPv6 to determine the total
    tunnel overhead amount.