I have an rb5009 trunked into a crs309. the rb5009 has all interfaces on a bridge, there is a management vlan interface (vlan 2) on that bridge, and I have an ip address on vlan 2 (192.168.2.1). the crs309’s management interface is on vlan 2, and its default gateway is set to the 192.168.2.1 . I started noticing these messages in the logs:
daemon.warning: Nov 30 00:18:10 crs309 crs309: sfp-sfpplus1: bridge RX looped packet - MAC [admin mac of the rb5009 bridge] -> [admin mac of the crs309 bridge] VID 2 ETHERTYPE 0x0800 IP TCP 192.168.6.105:36000 -> 192.168.2.3:22
After ruling out physical loops / stp issues, I decided to create a macvlan interface on top of vlan2 interface on rb5009 and assign a new mac to it, then assigned the ip address to the macvlan interface instead of directly to vlan2. This stopped the warnings in the logs. arp from the crs309 shows the new macvlan mac instead of the admin mac of the bridge.
So while I’m glad I seem to have cleaned up the logs a bit, I’m still a little confused as to why it showed up in the logs as a loop. Everything seemed to work fine before, I only noticed the log messages when I went looking for something else.