Notice of default tunnel type changes in Antrea 0.8.0

[Jianjun Shen]

Hello Antrea users and developers,

In Antrea 0.8.0 which is planned to be released in July 1st, we will change the default tunnel type (tunnel type takes effects only for 'trafficEncapMode' - 'encap' and 'hybrid') from VXLAN to Geneve.

Geneve supports extensible encapsulation headers which allow Antrea to add extra contexts to the encapsulated packets across Nodes. This is required by the Antrea Traceflow feature (see issue #631) which is expected to be released in Antrea 0.8.0.

When upgrading an existing K8s cluster that configured Antrea to use VXLAN tunnel type, there are two options to handle the default tunnel type change:

1. Edit the Antrea deployment YAML and explicitly set the 'tunnel_type" config option to 'vxlan` in 'antrea-agent.conf' of the  'antrea-config' ConfigMap. Then Antrea will keep using the VXLAN tunnel type after upgrade.

2. Swtich to the new default tunnel type. Then after the new version of Antrea agent starts, it will delete the old VXLAN tunnel port on the OVS bridge and create a new tunnel port of the Geneve type. So, before agents on all Nodes are upgraded and recreate the tunnel port, it is possible some Nodes are using the VXLAN tunnel type, while some others are using the Geneve tunnel type, and the traffic between the two sides will be dropped.

Please let us know for any concerns or suggestions for this change!

Cheers!

Jianjun