Open vSwitch Mirror Select-All Configuration

[0xBEN]

Hello, brief question.

I've got a handle of technical details of port mirroring on Open vSwitch, but one question remains:

With the select-all statement in the ovs-vsctl command, will this dynamically follow VMs and containers as they are started and shutdown? At any given time an interface for a VM or container could either exist or not exist on the switch depending on its state.

I've made a good effort to search the web for answers, even finding one blog that suggests the mirror doesn't follow VMs after full stop and start. Just looking for some clarification. Thank you in advance.

 

[0xBEN]

I did some controlled tests in my environment using both VMs and Linux Containers to see if Open vSwitch would dynamically forward traffic from newly created guests to the target port when the select-all parameter is set. I made sure to disable any jobs/scripts that monitor the port mirroring in case they might interfere with the testing.

My findings were that when I created new guests --- VMs and LXCs alike --- Open vSwitch automatically began forwarding the traffic dynamically from the new tap interfaces. So, there is no need to add any kind of monitoring functionality to scripts/jobs that might attempt to track when guests are added/removed when the select-all parameter is set.

For any kind of scenarios where specific guests would need to mirror to specific ports, it would probably be best to use hook scripts.