How to enable 802.11v 802.11k

Installing and Using OpenWrt Network and Wireless Configuration
#1

Dear all,

How do I enable 802.11v and k?
I cannot seem to find anything for 802.11k in hostapd documentation. I guess it is currently not possible?
For 802.11v hostapd mentions what i quoted below. Is it as easy as executing:
uci set wireless.bss_transistion=1

Thank you,

Ramon

##### IEEE 802.11v-2011 #######################################################

# Time advertisement
# 0 = disabled (default)
# 2 = UTC time at which the TSF timer is 0
#time_advertisement=2

# Local time zone as specified in 8.3 of IEEE Std 1003.1-2004:
# stdoffset[dst[offset][,start[/time],end[/time]]]
#time_zone=EST5

# WNM-Sleep Mode (extended sleep mode for stations)
# 0 = disabled (default)
# 1 = enabled (allow stations to use WNM-Sleep Mode)
#wnm_sleep_mode=1

# WNM-Sleep Mode GTK/IGTK workaround
# Normally, WNM-Sleep Mode exit with management frame protection negotiated
# would result in the current GTK/IGTK getting added into the WNM-Sleep Mode
# Response frame. Some station implementations may have a vulnerability that
# results in GTK/IGTK reinstallation based on this frame being replayed. This
# configuration parameter can be used to disable that behavior and use EAPOL-Key
# frames for GTK/IGTK update instead. This would likely be only used with
# wpa_disable_eapol_key_retries=1 that enables a workaround for similar issues
# with EAPOL-Key. This is related to station side vulnerabilities CVE-2017-13087
# and CVE-2017-13088. To enable this AP-side workaround, set the parameter to 1.
#wnm_sleep_mode_no_keys=0

# BSS Transition Management
# 0 = disabled (default)
# 1 = enabled
#bss_transition=1

# Proxy ARP
# 0 = disabled (default)
# 1 = enabled
#proxy_arp=1

# IPv6 Neighbor Advertisement multicast-to-unicast conversion
# This can be used with Proxy ARP to allow multicast NAs to be forwarded to
# associated STAs using link layer unicast delivery.
# 0 = disabled (default)
# 1 = enabled
#na_mcast_to_ucast=0
#2

I have these enabled on mine

uci set wireless.default_radio0.ieee80211r='1'
uci set wireless.default_radio0.ieee80211k='1'
uci set wireless.default_radio0.ieee80211v='1'
uci set wireless.default_radio0.wnm_sleep_mode='1'
uci set wireless.default_radio0.bss_transition='1'
uci set wireless.default_radio0.time_advertisement='2'
uci set wireless.default_radio0.time_zone='[time_zone_string]'

802.11k is RRM, look for that instead in the documentation. It's understood by /lib/netifd/hostapd.sh, if it's enabled, you'll see 2 rrm lines in /var/run/hostapd-phy0.conf

2 Likes
#3

Thanks! I switched on k and v now. As timezone I used CET-1CEST,M3.5.0,M10.5.0/3 (as found in /etc/TZ). And yes I do see the rrm lines in the conf.
How do i know it its working?

Note 802.11r does not seem to work for me... Clients lose internet access after they sleep somehow. And if i roam clients tend to disconnect then quickly do reconnect. Or do you think it may work now, with k and v enabled?

Thank you for your answer.

#4

You could check what the router sends out using wireshark https://weekly-geekly.github.io/articles/340140/

You only need 802.11r for fast transition to work, k and v are to provide additional information to help clients decide when to roam, they don't speed up the disconnect/reconnect process. For them to work, the client also needs to support these features (usually they do unless the hardware is fairly old). So when a client roams from one AP to another, both APs and the client need to support 802.11r for fast transition to work, and AP settings need to be compatible, e.g. same SSID, encryption/key, mobility domain, PMK etc, it's easier to use OpenWrt default (the example above uses default 802.11r settings)

If 802.11r is enabled, wpa_key_mgmt=WPA-PSK FT-PSK should appear in /var/run/hostapd-phy0.conf, FT-PSK wouldn't appear without 802.11r. Some apps could also show detailed WiFi diagnostic information.

WiFi client getting disconnected when it goes to sleep is not related to roaming, it's more to do with power saving. Most Android devices can be configured to keep WiFi connected in standby.

#5

Thanks again.
I can see that the two APs emit the K and V in the identification [WPA-EAP+EAP-SHA256-CCMP][RSN EAP+EAP-SHA256-CCMP][K][V][PMFC][ESS] and [WPA2-PSK+PSK-SHA256-CCMP][RSN PSK+PSK-SHA256-CCMP][K][V][PMFC][ESS] for the guestnet. Not sure if it contains any useful information or if the clients are using it. I have 2 identical APs (r7800) running the exact same latest stable openwrt to make things easier.

And yes if I add 802.11r it will transmit FT as well. But like i said, if i switch it on, then when e.g. my android phone after sleeping reconnects it does not have internet access, while it does show the Wifi symbol+signal strength, but then with an exclamation mark. I guess the STA is associated then but not authenticated anymore. I tried both the "generate PMK locally" as well as filling out the fields, made no difference. Maybe it has got to do with KRACK countermeasures, or maybe with 802.11w. I read somewhere that other ppl have an issue with that, though i tried switching to no avail. (I have that on optional at the moment, not really sure if that is needed or not.).

Thanks for any pointers.

#6

Default settings work for me. You could try other clients to see whether the problem is with the APs or with the client. You could also check OpenWrt log (logread) and Android log (adb).