Controllerless Networks

Recently we ran into an issue where a server in our environment was reachable by wired devices consistently but consistently not reachable by wireless devices. After some troubleshooting we were able to determine a joined the guest network had some how obtained the same IP address as the server in question. When traffic destined to that server reached the controller the traffic was dropped. We were able to recreate the same issue with a different server by statically setting its IP address on a cellphone and joining it to the guest network. My question is, is there any way to determine how the address got assigned to the device in the first place? Has anyone else ever seen behavior like this?

type "show user ip" will only tell you if the client got its address from dhcp or not.

If you are running ArubaOS 6.x, you can do this:

configure t
logging level debugging network process dhcpd subcat dhcp

Allow the client to connect, then type "show log network 50" to see where the client got its ip address from.

Do you mean that you have an IP overlap between the server segment and your guest network? Or are the servers and guest in the same network?

For many reasons, including clients taking server IP addresses, it is best practice to have servers, wired clients, and wireless clients in separate VLANs and IP ranges.