buletti:

Description

I have 3 WIFI access points (2x Netgear WNDR4300, 1x Netgear WNDR3700v2) running 19.07.4 r11208-ce6496d796. Each of those APs has a 2.4 GHz and a 5 GHz band. For each of the 2 radios I have defined 2 SSIDs: Home-net and Guest-net.
So each AP has a total of 4 WIFI interfaces:

• Home-net @ 2.4 GHz
• Home-net @ 5 GHz
• Guest-net @ 2.4 GHz
• Guest-net @ 5 GHz

All the WIFI interfaces of the same SSID are bridged together into a separate VLAN.

802.11r is configured identically on all 4 WIFI interfaces. I'm using a very simple FT config that generates the keys locally based on the pre-shared key and I let most of the required settings to be generated automatically.

Now, my problem is that fast-transitioning works for the Home-net, but not for the Guest-net.
Home-net roaming is really working great and as expected. I can fast-transition between the radio cells of the same AP (2.4GHz <=> 5GHz) as well as fast-transition between the cells of the different APs.

However fast-transitioning of the Guest-net on the other hand is not working at all. Even though it is essentially using the same configuration as the Home-net.
I already tried to provide explicit values for some of the relevant, generated 802.11r settings like NASID and Mobility-Domain, but that does not seem to make any difference.
I also did check what happens, if I delete the 2 working Home-net interfaces. Well, once they are deleted, the 2 remaining Guest-net interfaces started to work. I could then fast transition between the 2.4 and 5 GHz bands of the modified AP.
Given the fact that the previously defunct Guest-net started to function, I am kind of certain that my network configuration and 802.11r configuration are not the problem here.

How to reproduce:

//precondition//: a dual band AP with 19.07.04

1. for each of the 2 radios create 2 SSID pairs with the same name.
2. enable hostapd debug mode for both radios
3. connect to the first SSID with a mobile device and try to roam between the 2 bands
4. check the system log for FT messages
   //result//: FT is working for the first SSID
5. connect to the second SSID with a mobile device and try to roam between the 2 bands
6. check the system log for FT messages
   //result//: FT is not working for the second SSID
   //expected result//: FT is working for the second SSID

wireless configuration

config wifi-device 'radio0'
option type 'mac80211'
option hwmode '11g'
option path 'platform/ar934x_wmac'
option country 'DE'
option legacy_rates '0'
option htmode 'HT20'
option log_level '1'
option channel '11'
option txpower '17'

config wifi-iface 'wifinet3'
option device 'radio1'
option mode 'ap'
option network 'WIFI-GUEST'
option encryption 'psk2+ccmp'
option key 'redacted'
option ssid 'guest-net'
option wpa_disable_eapol_key_retries '1'
option ieee80211r '1'
option ft_psk_generate_local '1'
option ft_over_ds '0'
option max_inactivity '30'