IP conflict - Source IP and/or VLAN mismatch on MX64

[NickKova]

Hello,

Have bunch of events logged in MX64 event log, for 2 different devices, reachable over network with each having proper DHCP IP from default VLAN and pingable.  

Have one default VLAN 192.168.16.0/24 and Guest VLAN192.168.9.0/24. 

Can anyone elaborate on this, perhaps, what could be the cause for those events? I would really appreciate.

[RaphaelL]

2 devices from the same vendor ?

Were you able to take packet captures during the event ?

Client had the IP 169.254.xx.xx and was trying to source trafic on vlan 1 but your vlan 1 is probably not on subnet 169.254.xx.xx that's why.

[CptnCrnch]

Correct. You have a device within that Alan that is using an APIPA address (possibly because it hasn't received an IP via DHCP). As the MX doesn't have an address within this range, you're receiving these messages.

[NickKova]

Thank you guys, for your time and response. Thing is I am not sure how those devices can have APIPA address when DHCP from Meraki is working without issues. I have Unifi switch and all ports are configured with default profile targeting default VLAN with proper DHCP. That is what I do not get how is that possible. 

[alemabrahao]

It could be any cause, any chance of having a device with a fixed IP connected to a switch port that is on the incorrect VLAN?

It is not possible to reach a conclusion with the details you provided alone.

[cmr]

Do the MAC addresses listed also receive IP addresses from the DHCP server?

[NickKova]

Yes, those 2 devices have proper default VLAN IPs assigned, and they are online, no issues with them. 

[cmr · Accepted solution]

Then it is probably just that they were a bit slow to get an address and some data was sent from the 169 address.  I'd just ignore it unless it comes up all the time.

[NickKova]

Ok, sounds good. Than you!