Has anyone had trouble getting RoMON to work when passed through a PoE EdgeSwitch 24? It’s managed, and all I have are some VLANs configured. Full 1500-byte packets no problem, everything else working fine. No RoMON neighbours though, not with HAP lite, CRS, RB2011, or x86.
When connected directly, or through any other switch, RoMON works perfectly.
Do you have a packet capture? Does the Ethernet Header look ‘normal’ ?
I will capture packets tomorrow. In UBNT forums, I found another user with the same issue. Will report in both places.
I think it is a UBNT issue - this is what I posted over there:
I just checked myself about 5 min ago - it’s a special MAC address. It’s almost certainly consummed by the switch, that’s why it is not getting through.
The MAC address on my test network in use for Mikrotik RoMON, I believe, is:
Destination: Spanning-tree-(for-bridges)_88:bf (01:80:c2:00:88:bf)
which Wireshark flags as Spanning tree. From 802.1D-2004, table 7-10, this is outside the scope of the reserved range, which fall under the requirement:
7.12.6 Reserved addresses
Frames containing any of the group MAC Addresses specified in Table 7-10 in their
destination address field shall not be relayed by the Bridge.
The reserved range, from table 7-10, is
01-80-C2-00-00-00 to 01-80-C2-00-00-0F
I suspect that the internal filter on the UBNT switch maybe matches only 01-80-C2 or something like that, so drops the frame per 802.1D-2004, 7.12.6. Easy to test, but the vendor should be able to confirm.
Based on this, without any further documentation to the contrary, it is a UBNT bug incorrectly dropping these frames. Anyone else have any thoughts to refute the logic?
Ubiquiti has admitted that they are not passing these packets. They’ll look into allowing them. (The RFC implies that they should be passed, but does not make it explicit.)