I found myself an interesting situation yesterday. A coworker installed an AP in a location that we only had temporary physical access to and after we left, noticed it was setup as an Instant AP.
"No problem" I say to my coworker, log in to the web interface and convert to a Campus AP. However, I mistakenly put the IP address of the lab controller, not the production controller. Oops. The AP rebooted and joind the wrong controller.
At this point, the masterip was statically set and even though ADP is off on the lab controller, the AP kept joining the lab controller on subsequent reboots.
Anyway, to the meat of the post. Here's how I was able to change the environment variable for masterip without console access:
- Enable telnet in AP System
- Telnet to the AP
- Explore the CLI, find that you don't have permission for much and don't have the enable password. If anyone knows the enable password or how to set it, please let me know. I couldn't figure it out.
- After some exploring (using <tab><tab> to find commands), find the bootenv command.
- The bootenv command appears to be undocumented (from what I could find on Google) but offered a helpful hint:
Usage: bootenv <-s> | <-p name=value>
- Execute: bootenv -p masterip=<new IP>
- Reboot
- AP joined the new controller.
It appears you can use bootenv to set any of the env parameters - see this post for more details.
Hopefully this ends up being useful for someone else.