Mac clients have issues connecting and staying connected

[WalkerL]

Hello, All!

I recently installed a MR36, which is connected to an MX64 at a small office that did not have wifi prior.  Ever since we installed, there has been issues with our mac users connecting.  Under untagged traffic, it alerts 5/5 DNS failures and under VLAN 110, it shows 5/5 DHCP failures, and 1/1 ARP failures.  Checking the logs, it sometimes allows them to connect and shows healthy status, others it says either the DHCP server failed to respond, or that the DHCP is 166.166.x.x instead of the MX64.

The confusing thing is, the public IP that the meraki is showing is not the correct IP.  the correct public address starts with 206.83.x.x while the ip that shows the mac made a dhcp request to is 166.166.x.x

Looking this public ip up, it shows that it is a verizon ip address.   We havent had verizon there as the internet provider.  

I have copied other wifi profiles, as this doesn't happen anywhere else, changed the SSID, created a new profile from scratch, contacted support, etc.  I've read that there is an issue with the mac address randomization that apple devices have, but the links that showed that as the issue, never offered any solutions.

This hasn't happened at any other location, i am just lost on what to do next.  We have a small meraki switch I am installing next week, but i don't believe that will fix it.  

Has anyone run into similar situations? Or could possibly help point me in the right direction?

Thanks.

[BlakeRichardson]

What firmware are you running on the MR and MX?

Also what authentication method are using using on that SSID? 

Is this a flat network or do you have multiple VLANS? If you have multiple VLANS what happens when you connect to that VLAN using ethernet instead of Wifi, does it work as expected? 

[WalkerL]

The mx is running MX 16.16

The AP is running MR 28.6.1

I've open the authentication as to simplify for testing reasons, and the issue persists.  No vlans either aside from the default vlan.  

When hardwired into the firewall or the dummy switch, it works fine.  They are online and have no loss of service.

[PhilipDAth]

It smells like you have two Internet circuits and two routers plugged into the same switch.  Sometimes users are using DHCP from one and sometimes from the other, causing the public IP address to change.

The other possibility is both routers are using the same internal IP, which would cause intermittent outages for the users.

[WalkerL]

I will check that again and make sure.  The MX right now is what should be handing out the dhcp addresses which it does when clients are connected via lan cable.  I would think though that it would affect all the computers and not just the mac books on the network.  

At the moment looking at the dashboard, the windows machine on the wifi has the correct address, 10.111.221.x subnet, while the macbook has that 166.166.75.244 address.

I will double check though what is plugged into that switch.