https://github.com/containernetworking/plugins/issues/951

Add "activateInterface" option to bridge plugin CNI.
The option will control whether the defined interface will be brought up by the plugin. The default will be true.
This is required in case some other CNI in the plugin chain wants to modify the interface before it is brought up and made visible to the network.

For example, in case I want to prevent my interface to send any IPv6 traffic. I can use a another CNI to achieve this by setting net.ipv6.conf.all.disable_ipv6 to 1.
But since the bridge CNI will first activate the interface, it may send IPv6 data (NDP) on activation, before the next CNI disables it.
Having activateInterface=false will solve this issue. The bridge CNI will create and configure the interface and the next CNI in the chain will apply the sysctl and activate the interface,