group_forward_mask

A mask of group addresses to forward.

Usually, group addresses in the range from 01:80NMSettingBridge:C2:00:00:00 to 01:80NMSettingBridge:C2:00:00:0F are not forwarded according to standards. This property is a mask of 16 bits, each corresponding to a group address in that range that must be forwarded. The mask can't have bits 0, 1 or 2 set because they are used for STP, MAC pause frames and LACP.