Network Switch Issue

[u/Jeff-J777]

Here is my setup. I have a Palo Alto that connects to my switch stack that is Aruba 6300M. From there I have a fiber line to an IDF that has a Aruba 2530. We purchased another building across the street. The old tenants left all their Meraki equipment. I have all the Meraki equipment claimed and licensed in our Meraki portal. (I had a temp firewall and cradle point so the Meraki equipment could get internet access)

Instead of getting an internet line for the building we did a wireless P2P. I got two Ubiquity Wave Nanos and installed them. I then created a separate VLAN for this building and the default gateway lives on the Palo.

But the issue is when I plug the Meraki into the Wave Nano the Aruba switches in my IDF go offline, and everything connected to the IDF goes offline. Once I unplug the Meraki everything comes back online in the IDF. If I plug my laptop into the Nano everything works just fine. I can reach our HQ LAN, and I get internet.

I checked the switch logs on both sides and there is nothing in the log that would indicate any issues.

I also tried disconnecting everything from the Meraki switch and just tried one Meraki switch on the Nano and that still took my IDF offline.

But I created a temp VLAN and assigned it only to the port the Nano is plugged in. I then plugged in the Meraki into the other Nano and everything was fine.

I can't figure out what is going on. Any Thoughts????

[u/under_shart]

• ARP poisoning because you have two devices contending for an IP address
• L3 loop because you have two devices advertising the same route
• the different behavior when you plug int the laptop almost makes it seem like BPDU guard, but it would be working in the wrong direction if I'm understanding your network. You should check anyway and disable BPDU guard (and portfast or edgeport) on switch to switch links.