Hi,
Does anyone know how to drop DTP frames egressing from a bridge port? Our local internet exchange is complaining that they are seeing DTP packets from us.
5 2.063925227 Cisco_c7:45:8b → CDP/VTP/DTP/PAgP/UDLD DTP 60 Dynamic Trunk Protocol
6 2.063933888 Cisco_c7:45:8b → CDP/VTP/DTP/PAgP/UDLD DTP 60 Dynamic Trunk Protocol
Either using /interface bridge filter to drop these packets, or by setting protocol-mode of the bridge to something else than none, but in the latter case the adjacent devices may complain about RSTP or MSTP BPDUs coming from you. So chain=forward out-interface=the-interface-facing-the-complaining-device dst-mac-address=01:00:0C:CC:CC:CC/FF:FF:FF:FF:FF:FF action=drop should do the trick for all Cisco proprietary protocols (they use the same multicast MAC address). If your Mikrotik device is a CRS or a SOHO one with one of the better switch chips, an equivalent switch chip rule will do the same with less CPU load.