This is not causing any issues. I just find it interesting. SNMP monitoring is reporting MAC address changes on remote devices. ARP on opnsense box does NOT show the same.
I've got an observium instance on a proxmox VM that pulls data from a number of systems, including opnsense. The opnsense box has multiple physical interfaces. I'm certain this is an snmp bug, whether on the opnsense side or possibly the observium side.
So, let's say a MAC address is aa:bb:cc:dd:ee:ff. SNMP from opnsense is reporting 3 different MAC addresses over the course of weeks:
- aa:bb:cc:dd:ee:ff
- 00:bb:cc:dd:ee:ff
- aa:00:00:00:00:00
Not all changing MAC's show all three patterns. Not all devices show changing MACs. I do see changing MACs on all five NICs.
Currently, my observium instance reports my ISP router MAC as changing from the first form to the last on the list five hours ago. An arp (both via GUI and commandline) reports the correct MAC.
Again, this is not a big deal. I'm not even looking for a fix. I am curious if anyone has seen anything similar?
I am running the community edition, 26.1.9. Since commissioning my system on 2nd of June, LibreNMS is not reporting any MAC changes. LibreNMS gets its data from SNMP.