In commit https://github.com/vyos/vyatta-cfg-quagga/commit/25d3ee90522b1056d9a25735c3e0c89e7b1eeae1#diff-5d59f3112c0c1adb70e3a081ec67e002 the 'additive' option was removed.
It would be good to have the option to add communities in route-map rules, instead of always replacing existing.
I have situations where i would like to keep the received communities from providers, and also internally routes pass multiple routers and adding communities is a nice option to have.

It seems the verification script vyatta_quagga_utils.pl does have the additive option. So i tested by allowing it during configuration and it works.