Quagga inside a VE CT requires 3 Linux capabilities configured for the container on the hostnodehost node:

vzctl set <id> CTID --capability net_admin:on --save vzctl set <id> CTID --capability net_raw:on --save vzctl set <id> CTID --capability sys_admin:on --save

Note: {{Warning|granting capabilities for a container can have reduced security implications - ensure you fully understand the repercussions of granting any of the above capabilities before using in production.}}