OpenWrt/LEDE Project

Attached to Project: OpenWrt/LEDE Project
Opened by buletti - 26.11.2020

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 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 a test to see what happens, if I delete the 2 working Home-net interfaces. Well, once they are deleted, fast transitioning via the 2 remaining Guest-net interfaces started to work. I could easily roam between the 2.4 and 5 GHz networks of the modified AP.
Given the fact that the previously defunct Guest-net network becomes functional tells me that my network configuration and my 802.11r configuration are not the problem here.

How to reproduce:

precondition: a dual band AP with 19.07.04
1. set up 2 wifi networks for each radio
2. enable hostapd debug mode for both radios
3. connect with a mobile device to the first SSID and try to roam between the bands
4. check the systemlog for FT messages
result: fast transitioning is working for the first SSID
5. connect with a mobile device to the second SSID and try to roam between the bands
6. check the systemlog for FT messages
result: fast transitioning is not working for the second SSID
expected result: fast transitioning is working for both/all SSIDs.

wireless config

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-device 'radio1'
	option type 'mac80211'
	option hwmode '11a'
	option path 'pci0000:00/0000:00:00.0'
	option country 'DE'
	option legacy_rates '0'
	option htmode 'HT40'
	option log_level '1'
	option channel '36'    

## home-net 2.4 GHz
config wifi-iface 'default_radio0'
	option device 'radio0'
	option mode 'ap'
	option network 'WIFI-HOME'
	option encryption 'psk2+ccmp'
	option key '***redacted***'
	option ssid 'home-net'
	option macfilter 'allow'
	list maclist '***redacted***'
	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'

## home-net 5 GHz
config wifi-iface 'default_radio1'
	option device 'radio1'
	option mode 'ap'
	option network 'WIFI-HOME'
	option encryption 'psk2+ccmp'
	option key '***redacted***'
	option ssid 'home-net'
	option macfilter 'allow'
	list maclist '***redacted***'
	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'

## guest-net 2.4 GHz
config wifi-iface 'wifinet2'
	option device 'radio0'
	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'

## guest-net 5 GHz
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'