I have LACP configured between two CRS326-24S+2Q+RM (on the 40GBps interfaces) and a CRS326-24S+2Q+RM and 8 CRS328-24P-4S+ (using 2 10Gbps interfaces). For some reason, IP addresses are duplicated across the network with different MAC addresses, especially for the switches. I am guessing this is not normal, anything I can provide to help determine what is causing the issue and how to resolve it?
What exactly means “IP addresses are duplicated across the network with different MAC addresses”? That in the ARP tables of some devices in the network, an IP address is shown with MAC address X, and in the ARP tables of other devices, the same IP address is shown with MAC address Y, or you actually had in mind something completely else?
It shows most often in WinBox, but one of the CRS326-24S+2Q+RM switches will show 2+ entries with different MAC addresses. And our router (a Meraki MX95) would send alerts saying it saw the same IP with different MAC addresses associated with it. For now, I have one interface associated with each LACP disabled on our primary CRS326-24S+2Q+RM switch.
Can you show the output /ip arp print where address=the.ip.add.ress on a Mikrotik device where you see this?
It is blank. That being said here is the WinBox list and the Neighbor list of our main CRS326-24S±2Q+RM
This seems normal to me. All the neighbor discovery protocols (MNDP, CDP, LLDP) work at “physical” interfaces, i.e. even if two interfaces are bonded together, these protocols work at each of them separately. So nothing to worry about.
OK. I will have to re-enable the interfaces and turn on duplicate discovery on the Meraki again. See if I get the notifications again.
The MNDP packets are normal IP/UPD ones, so if the Meraki looks at (source MAC address, source IP address) tuples, it will keep showing duplicates. At the Mikrotik side, you can only disable neighbor discovery at the interfaces facing towards the Meraki.