Cisco WIFI and Fast transition trouble

[Service Informatique]

hello and sorry for my english,

Yesterday we had trouble to connect payment terminal to my wifi, nothing to do, the terminal don't want to connect to the wifi and exactly the same with an other terminal. I have no trouble with computers on the same wifi !

Si, i process with debug on Cisco Controler, and the debug said that there was trouble with FAST TRANSITION. And in the WLAN configuration (in security) i found that "fast transition" was on "adaptive". So i disabled Fast Transition and after that the 2 terminals can now connect.

My question are :

I have to keep "fast transition" ON or not ? 
If i have to allow Fast transition, i need to select "adaptive" or "Enable"
It is also a public wifi, there is a lot of phone connect on it, i have to allow fast transition ?

thanks a lot

[Flavio Miranda]

I have to keep "fast transition" ON or not ? 

For terminal, which does not move, you dont need fast transition. 

If i have to allow Fast transition, i need to select "adaptive" or "Enable"

Adaptive is better then Enable for obvious reason as you could see. Not all devices support it and a lot of them have problem with that.

It is also a public wifi, there is a lot of phone connect on it, i have to allow fast transition ?

If you can create two separates SSID would be a good idea but in case you can not, then, keep FT disabled.   I prefer disable it.

[Service Informatique]

You sure it is better to disable it ?

[Flavio Miranda · Accepted solution]

Yeah. This is about roaming fastly.  But, the problem is, not always the device undestand this kind of feature and this can cause problem. 

If you want to use it, I recommend  you firstly create a PoC (prove of concept) and test your devices to make sure they can benefit of this feature. 

Otherwise, keep it disable and avoid problems.