neutron/releasenotes/notes/overlay_ip_version-ml2-e6438b570844ef5c.yaml
Brian Haley 51a697817d Change tunnel MTU calculation to support IPv6
The IPv6 header is twice the size of the IPv4 header, 40 vs 20
bytes, but the tunnel overhead constants are static, only
accounting for an IPv4 header in all cases.  In order to be
correct it needs to treat the tunnel overhead different from
the IP overhead at L3.

This required removing the 20 byte IP overhead from the tunnel
type overhead constants and creating a new option,
ml2.overlay_ip_version, in order for the server to know which
version will be used, since it calculates the MTU for the network.
A version mis-match will now cause a tunnel sync to fail on
the server.

Moved all MTU tests to a common location to remove duplication.

DocImpact

Change-Id: Ia2546c4c71ff48b9fe2817fbad22b1fbf85f325b
Closes-bug: #1584940
2016-07-05 18:07:29 -04:00

18 lines
766 B
YAML

---
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.