Wireless Access

We recently added about 30 APs to a site. All but 6 of them came up just fine. The others will register and appear in the AP Installation page for about 30 seconds and then disappear. They are all connected to the same switch. I was told there is a setting that I can change to try and get them to stay connected but I am unable to find it. I suspect my problems are layer 1 related, but I wanted to see if there is something I can do in the interim.

When those come up and you please do a show ap database and see if there's any flags ?

Make sure you have the right amount of AP licenses installed : show ap license-usage

You can also  pick one of the IP addresses from the APs and do a show datapath session table <ipaddress> and see if there's anything getting denied from the controller perspective 

The last thing you could check is the show log system 100 and if there's any system error messages related to the APs

Licenses are fine. When the APs show up briefly, and show the D flag. I'll check the logs and other.

Thanks for the info.

The D flag means D = Dirty or no config and there's communication issues between the APs and the controllers 

Can you plug the AP directly to the controller and see if it comes up ?

Check the following :

show profile-errors 

Do you by any chance by two controller master-local on two different AOS ?

What AOS are you using ?

Please read this : 

https://arubanetworkskb.secure.force.com/pkb/articles/Troubleshooting/D-flag-troubleshooting

https://arubanetworkskb.secure.force.com/pkb/articles/FAQ/Why-do-AP-s-go-into-Dirty-flag-How-can-we-troubleshoot-this-symptom