Force 300-25 mysteriously autoconnecting with no APs selected?

Had an incident today with a F300-25 running

The F300-25 had been used as a back haul master and was recently replaced with a F300-CSM. We had killed the POE power to the radio at the switch when we installed the new back haul and its been sitting on the tower for a few weeks. I decided to power it up today and change it over to SM mode for reuse as we were pulling it down this coming weekend during a tower climb.

The unit powered up fine and I changed it from AP TDD Master to just SM TDD, and removed all frequencies except one way down in the low band well away from anything on the tower.

Hit save with the required a reboot. After the reboot we lost communication with the tower requiring a truck roll. When we arrived on site we immediately disconnected the F300-25 and everything recovered, so indications were some type of loop which shouldn’t have been possible.

Leaving the unit disconnected from the network, we powered it up from a brick I was able to log into the unit and was surprised by what I found.

The GUI showed everything as I had set it, SM mode, with a single low frequency ticked and no active APs in its list. However, the frequency list showed green, indicating connected/registered on the frequency of the local ePMP 1000 AP, even though the frequency was not selected, nor were there any APs listed at all

I verified it was in fact connected and I could access the network and internet through it. A reload/refresh of the GUI did not change anything.

Why or how would the unit connect to an AP that is not in its AP list nor the appropriate frequency ticked. Changing two options under the same save a big NoNo possibly?

It obviously did change to SM mode but equally obviously did not clear the AP list nor reset the frequency list, even though the GUI “showed” it did.

I was able to add an AP to the list and tick the appropriate frequency and everything showed correctly after it saved and rebooted and sitting idle. How or why it was in this half state and reporting its configuration falsely is a mystery.

Not that this is an every day occurrence and in most cases would have just generated a “that’s weird” but in this case did result in about a 30 minute outage for that tower due to the truck roll.

Thought I would put it out there and spice it up a bit. Hasn’t been much of interest on here lately. Still waiting, waiting, waiting patiently for the official 4.6.2.

IIRC, SM’s will connect to the strongest AP when there’s nothing in their list… although I can’t explain why it would connect without the center frequency of the e1k AP selected. :man_shrugging:

Maybe use the config test function next time?

Under configuration, security, if you have a password set, it will try to use that password to connect to any APs it can see. Regardless of whether they are in the AP list or not. I believe changing from AP to SM keeps the same security settings that may have caused this.