Stable/2.0

If I am working on a bugfix for a feature that is new to stable/2.0 ( See https://github.com/FRRouting/frr/wiki/Quagga-1.1-%E2%86%92-FRR-2.0 ) I pull a branch against that for the bug fix.

Stable/3.0

If I am working on a bugfix for a feature that is new to stable/3.0 ( See https://github.com/FRRouting/frr/wiki/FRR-2.0-%E2%86%92-FRR-3.0 ) I pull a branch against that for the bug fix.

master

If I am working on a bugfix for a feature that is new in master ( See https://github.com/FRRouting/frr/wiki/Major-Changes ) I pull a branch against that for the bug fix. Also if I am adding a new feature I pull a branch against master currently