[ovs-discuss] Tunnel liveliness in flow based tunneling

[Liran Schour]

While with ordinary tunnels, liveliness should be handled by the management
layer who creates the tunnels. And when a remote host goes down or lost
connectivity the vport that represent the tunnel to that host and all the
flows that output to this vport should be removed from all hosts by that
management layer.

However in flow based tunneling we can have a thinner management layer and
we can assume that as long that there is a tunnel based on a flow with a
specific dst_ip that dst_ip is a live. But currently if a remote host goes
down the flow will still point to that remote host without any notification
mechanism.

A trivial solution will be to create a daemon on each host that will go
over all the tunnel flows and will verify liveliness of the remote hosts.
In case of connectivity lost, the daemon will remove all tunnel flows that
points to that remote host and by that will force the Vswitch to ask the
controller for a new flow.

Are there any thoughts to create such built-in solution inside Openvswitch
for flow based tunneling?

Any other thoughts?

Thanks,
- Liran