Android connectivity issues

Robert Senger robert.senger at lists.microscopium.de
Mon Sep 7 14:53:26 EDT 2015


Hi all,

First of all, sorry for the lengthy logs below. I am having trouble with
some Android 4.4.4 KitKat devices connecting to hostapd. The devices
connect fine, data flow is also fine for about 20 to 30 minutes, then
the data flow stops. No more ping, nothing, for about 5 to 15 minutes.
Then suddenly data flow is fine again. The wifi connection never drops,
and on the devices, the wifi icon indicates that there are packets sent
all the time. 

Below a tcpdump recorded on the router, during a period where data flow
is dead (snippet from several hundreds of similar lines, started 5
minutes before):

13:19:37.225540 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:19:37.225604 ARP, Reply prokyon-wlan0_0.microscopium.de is-at 02:a5:04:3d:96:11 (oui Unknown), length 28
13:19:37.225630 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:19:38.205590 IP6 fe80::6677:91ff:feda:72f4 > fe80::a5:4ff:fe3d:9611: ICMP6, neighbor solicitation, who has fe80::a5:4ff:fe3d:9611, length 32
13:19:38.205752 IP6 fe80::a5:4ff:fe3d:9611 > fe80::6677:91ff:feda:72f4: ICMP6, neighbor advertisement, tgt is fe80::a5:4ff:fe3d:9611, length 24
13:19:38.205796 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:19:38.205828 ARP, Reply prokyon-wlan0_0.microscopium.de is-at 02:a5:04:3d:96:11 (oui Unknown), length 28
13:19:38.205842 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:19:39.205633 IP6 fe80::6677:91ff:feda:72f4 > fe80::a5:4ff:fe3d:9611: ICMP6, neighbor solicitation, who has fe80::a5:4ff:fe3d:9611, length 32
13:19:39.205780 IP6 fe80::a5:4ff:fe3d:9611 > fe80::6677:91ff:feda:72f4: ICMP6, neighbor advertisement, tgt is fe80::a5:4ff:fe3d:9611, length 24
13:19:39.205823 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:19:39.205857 ARP, Reply prokyon-wlan0_0.microscopium.de is-at 02:a5:04:3d:96:11 (oui Unknown), length 28
13:19:39.205871 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:19:40.205903 IP6 fe80::6677:91ff:feda:72f4 > fe80::a5:4ff:fe3d:9611: ICMP6, neighbor solicitation, who has fe80::a5:4ff:fe3d:9611, length 32
13:19:40.206051 IP6 fe80::a5:4ff:fe3d:9611 > fe80::6677:91ff:feda:72f4: ICMP6, neighbor advertisement, tgt is fe80::a5:4ff:fe3d:9611, length 24
13:19:41.125577 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:19:41.125639 ARP, Reply prokyon-wlan0_0.microscopium.de is-at 02:a5:04:3d:96:11 (oui Unknown), length 28
13:19:41.125664 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:19:41.138584 IP6 fe80::a5:4ff:fe3d:9611 > ip6-allnodes: ICMP6, router advertisement, length 144
13:19:42.125564 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:19:42.125625 ARP, Reply prokyon-wlan0_0.microscopium.de is-at 02:a5:04:3d:96:11 (oui Unknown), length 28
13:19:42.125653 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:19:43.125513 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:19:43.125578 ARP, Reply prokyon-wlan0_0.microscopium.de is-at 02:a5:04:3d:96:11 (oui Unknown), length 28
13:19:43.125603 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28

So, the device is sending thousands of ARP requests, but does not seem
to accept the answer. No other packets are detected during that period.

After a while, usually 5 to 15 minutes, the connection becomes fine
again. This is what I see in the tcpdump:

13:20:02.146162 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:20:02.146260 ARP, Reply prokyon-wlan0_0.microscopium.de is-at 02:a5:04:3d:96:11 (oui Unknown), length 28
13:20:02.146285 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:20:03.146317 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:20:03.146381 ARP, Reply prokyon-wlan0_0.microscopium.de is-at 02:a5:04:3d:96:11 (oui Unknown), length 28
13:20:03.146407 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:20:03.834678 IP prokyon-wlan0_0.microscopium.de > pim-routers.mcast.net: PIMv2, Bootstrap, length 36
13:20:05.378636 IP6 fe80::a5:4ff:fe3d:9611 > ip6-allnodes: ICMP6, router advertisement, length 144
13:20:12.128071 IP6 fe80::a5:4ff:fe3d:9611 > ip6-allnodes: ICMP6, router advertisement, length 144
13:20:20.535584 IP6 fe80::a5:4ff:fe3d:9611 > ip6-allnodes: ICMP6, router advertisement, length 144
13:20:24.372069 IP6 fe80::a5:4ff:fe3d:9611 > ip6-allnodes: ICMP6, router advertisement, length 144
13:20:28.748746 EAPOL key (3) v2, len 127
13:20:29.378680 IP prokyon-wlan0_0.microscopium.de > pim-routers.mcast.net: PIMv2, Hello, length 10
13:20:29.750029 EAPOL key (3) v2, len 127
13:20:30.747965 IP6 fe80::a5:4ff:fe3d:9611 > ip6-allnodes: ICMP6, router advertisement, length 144
13:20:30.751335 EAPOL key (3) v2, len 127
13:20:31.137331 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32
13:20:31.752458 EAPOL key (3) v2, len 127
13:20:32.134330 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32
13:20:33.134330 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32
13:20:34.380976 IP prokyon-wlan0_0.microscopium.de > pim-routers.mcast.net: PIMv2, Bootstrap, length 36
13:20:34.494466 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32
13:20:35.494318 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32
13:20:35.500874 IP6 fe80::a5:4ff:fe3d:9611 > ip6-allnodes: ICMP6, router advertisement, length 144
13:20:36.494333 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32
13:20:37.958484 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32
13:20:38.958370 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32
13:20:39.958329 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32
13:20:40.917807 IP6 fe80::a5:4ff:fe3d:9611 > ip6-allnodes: ICMP6, router advertisement, length 144
13:20:41.403627 64:77:91:da:72:f4 (oui Unknown) > Broadcast Null Unnumbered, xid, Flags [Response], length 6: 01 00
13:20:41.412045 EAPOL key (3) v2, len 117
13:20:41.453342 EAPOL key (3) v1, len 135
13:20:41.455674 EAPOL key (3) v2, len 151
13:20:41.458345 EAPOL key (3) v1, len 95
13:20:42.328723 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 64:77:91:da:72:f4 (oui Unknown), length 300
13:20:42.328847 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from 64:77:91:da:72:f4 (oui Unknown), length 300
13:20:42.730516 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32
13:20:43.158936 IP prokyon-wlan0_0.microscopium.de.bootps > deneb.microscopium.de.bootpc: BOOTP/DHCP, Reply, length 300
13:20:43.287925 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:20:43.287971 ARP, Reply prokyon-wlan0_0.microscopium.de is-at 02:a5:04:3d:96:11 (oui Unknown), length 28
13:20:43.288031 ARP, Request who-has prokyon-wlan0_0.microscopium.de tell deneb.microscopium.de, length 28
13:20:43.292422 IP deneb.microscopium.de.42698 > prokyon-wlan0_0.microscopium.de.domain: 52073+ A? dailymotion-mobile-compute.appspot.com. (56)
13:20:43.321709 IP prokyon-wlan0_0.microscopium.de.domain > deneb.microscopium.de.42698: 52073 2/4/4 CNAME appspot.l.google.com., A 64.233.184.141 (239)
13:20:43.407841 IP deneb.microscopium.de.36099 > waspproxy.googlemail.com.http: Flags [S], seq 2440458997, win 14600, options [mss 1460,sackOK,TS val 90491 ecr 0,nop,wscale 6], length 0
13:20:43.427440 IP waspproxy.googlemail.com.http > deneb.microscopium.de.36099: Flags [S.], seq 2950162479, ack 2440458998, win 42540, options [mss 1360,sackOK,TS val 1183829258 ecr 90491,nop,wscale 7], length 0
13:20:43.431272 IP deneb.microscopium.de.36099 > waspproxy.googlemail.com.http: Flags [.], ack 1, win 229, options [nop,nop,TS val 90501 ecr 1183829258], length 0
13:20:43.730341 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32
13:20:44.001014 IP prokyon-wlan0_0.microscopium.de.bootps > deneb.microscopium.de.bootpc: BOOTP/DHCP, Reply, length 300
13:20:44.017642 IP deneb.microscopium.de > prokyon-wlan0_0.microscopium.de: ICMP deneb.microscopium.de udp port bootpc unreachable, length 336
13:20:44.488665 IP6 :: > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28
13:20:44.488801 IP6 :: > ff02::16: HBH ICMP6, multicast listener report v2, 1 group record(s), length 28
13:20:44.596859 IP deneb.microscopium.de > 239.255.255.250: igmp v2 report 239.255.255.250
13:20:44.597004 IP deneb.microscopium.de > 239.255.255.250: igmp v2 report 239.255.255.250
13:20:44.631578 IP deneb.microscopium.de.1900 > 239.255.255.250.1900: UDP, length 125
13:20:44.631702 IP deneb.microscopium.de.1900 > 239.255.255.250.1900: UDP, length 125
13:20:44.730320 IP6 fe80::a5:4ff:fe3d:9611 > ff02::1:ffa5:fc: ICMP6, neighbor solicitation, who has 2001:470:52a0:303:7067:be4b:1ea5:fc, length 32

The device reassociates/reauthenticates, and after that IP data flow is
fine again. 

Hostapd log is not very helpful. There's nothing logged at the time the
problems begin, all I can see is the reauthentication after which data
flow is fine again.

All other devices, including other Android hardware/software versions,
do not show this strange behaviour. I would assume that it's mainly a
problem of the specific device, but it seems that I am the only poor guy
in the (google) world having wifi connections with those specific
devices...

So I wonder if there's anything I can do on the hostapd side to help
those devices keeping their connectivity.

I already tried several settings on the Android device, tried WPA2-PSK
instead of WPA2-EAP, no change.

Will try with another AP (consumer router) tonight.

Thanks for help.

Robert


-- 
Robert Senger




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