Dropping wireless clients on RB751U-2HnD

rotten777 · Fri Jun 29, 2012 2:28 am

So I have changed very little to the wireless setup on the rb. Set to AP bridge, b/g/n, 20mhz channel width, 2462 freq, ssid, wireles proto to 802.11, setup WPA2 key. Clients connect, then drop, then reconnect, then drop, then reconnect, then drop. Never ending loop. Quite frustrating. It's on androids, ipads, linux laptop, windows laptop, pretty much everything wireless has the same symptoms.

rotten777 · Fri Jun 29, 2012 2:34 am

I am also seeing dropped packets and ping replies all over the map from 18ms to 450ms to timeouts

rotten777 · Fri Jun 29, 2012 2:42 am

PING 192.168.77.1 (192.168.77.1) 56(84) bytes of data.
64 bytes from 192.168.77.1: icmp_req=1 ttl=64 time=166 ms
64 bytes from 192.168.77.1: icmp_req=2 ttl=64 time=190 ms
64 bytes from 192.168.77.1: icmp_req=3 ttl=64 time=8.97 ms
64 bytes from 192.168.77.1: icmp_req=4 ttl=64 time=35.2 ms
64 bytes from 192.168.77.1: icmp_req=5 ttl=64 time=55.3 ms
64 bytes from 192.168.77.1: icmp_req=6 ttl=64 time=80.0 ms
64 bytes from 192.168.77.1: icmp_req=7 ttl=64 time=100 ms
64 bytes from 192.168.77.1: icmp_req=8 ttl=64 time=9.37 ms
64 bytes from 192.168.77.1: icmp_req=9 ttl=64 time=977 ms
64 bytes from 192.168.77.1: icmp_req=10 ttl=64 time=1000 ms
64 bytes from 192.168.77.1: icmp_req=11 ttl=64 time=0.960 ms
64 bytes from 192.168.77.1: icmp_req=12 ttl=64 time=23.4 ms
64 bytes from 192.168.77.1: icmp_req=13 ttl=64 time=46.2 ms
64 bytes from 192.168.77.1: icmp_req=14 ttl=64 time=69.3 ms
64 bytes from 192.168.77.1: icmp_req=15 ttl=64 time=92.3 ms
64 bytes from 192.168.77.1: icmp_req=16 ttl=64 time=115 ms
64 bytes from 192.168.77.1: icmp_req=17 ttl=64 time=138 ms
64 bytes from 192.168.77.1: icmp_req=18 ttl=64 time=161 ms
64 bytes from 192.168.77.1: icmp_req=19 ttl=64 time=184 ms
64 bytes from 192.168.77.1: icmp_req=20 ttl=64 time=207 ms
64 bytes from 192.168.77.1: icmp_req=21 ttl=64 time=230 ms
64 bytes from 192.168.77.1: icmp_req=22 ttl=64 time=254 ms
64 bytes from 192.168.77.1: icmp_req=23 ttl=64 time=277 ms
64 bytes from 192.168.77.1: icmp_req=24 ttl=64 time=300 ms
64 bytes from 192.168.77.1: icmp_req=25 ttl=64 time=324 ms
64 bytes from 192.168.77.1: icmp_req=26 ttl=64 time=346 ms
64 bytes from 192.168.77.1: icmp_req=27 ttl=64 time=369 ms
64 bytes from 192.168.77.1: icmp_req=28 ttl=64 time=392 ms
64 bytes from 192.168.77.1: icmp_req=29 ttl=64 time=416 ms
64 bytes from 192.168.77.1: icmp_req=30 ttl=64 time=439 ms
64 bytes from 192.168.77.1: icmp_req=31 ttl=64 time=462 ms
64 bytes from 192.168.77.1: icmp_req=32 ttl=64 time=485 ms
64 bytes from 192.168.77.1: icmp_req=33 ttl=64 time=508 ms
64 bytes from 192.168.77.1: icmp_req=34 ttl=64 time=531 ms
64 bytes from 192.168.77.1: icmp_req=35 ttl=64 time=554 ms
64 bytes from 192.168.77.1: icmp_req=36 ttl=64 time=578 ms
64 bytes from 192.168.77.1: icmp_req=37 ttl=64 time=601 ms
64 bytes from 192.168.77.1: icmp_req=38 ttl=64 time=624 ms
64 bytes from 192.168.77.1: icmp_req=39 ttl=64 time=648 ms
64 bytes from 192.168.77.1: icmp_req=40 ttl=64 time=775 ms
64 bytes from 192.168.77.1: icmp_req=41 ttl=64 time=800 ms
64 bytes from 192.168.77.1: icmp_req=42 ttl=64 time=825 ms
64 bytes from 192.168.77.1: icmp_req=43 ttl=64 time=850 ms
64 bytes from 192.168.77.1: icmp_req=44 ttl=64 time=875 ms
64 bytes from 192.168.77.1: icmp_req=45 ttl=64 time=900 ms
64 bytes from 192.168.77.1: icmp_req=46 ttl=64 time=925 ms
64 bytes from 192.168.77.1: icmp_req=47 ttl=64 time=951 ms
64 bytes from 192.168.77.1: icmp_req=48 ttl=64 time=974 ms
64 bytes from 192.168.77.1: icmp_req=49 ttl=64 time=1000 ms
64 bytes from 192.168.77.1: icmp_req=50 ttl=64 time=0.742 ms
64 bytes from 192.168.77.1: icmp_req=51 ttl=64 time=22.9 ms
64 bytes from 192.168.77.1: icmp_req=52 ttl=64 time=46.9 ms
64 bytes from 192.168.77.1: icmp_req=53 ttl=64 time=70.5 ms
64 bytes from 192.168.77.1: icmp_req=54 ttl=64 time=93.3 ms
64 bytes from 192.168.77.1: icmp_req=55 ttl=64 time=116 ms
64 bytes from 192.168.77.1: icmp_req=56 ttl=64 time=139 ms
64 bytes from 192.168.77.1: icmp_req=57 ttl=64 time=162 ms
64 bytes from 192.168.77.1: icmp_req=58 ttl=64 time=185 ms
64 bytes from 192.168.77.1: icmp_req=59 ttl=64 time=211 ms
64 bytes from 192.168.77.1: icmp_req=60 ttl=64 time=233 ms
64 bytes from 192.168.77.1: icmp_req=61 ttl=64 time=143 ms
64 bytes from 192.168.77.1: icmp_req=62 ttl=64 time=169 ms
64 bytes from 192.168.77.1: icmp_req=63 ttl=64 time=86.7 ms
64 bytes from 192.168.77.1: icmp_req=64 ttl=64 time=6.86 ms
64 bytes from 192.168.77.1: icmp_req=65 ttl=64 time=30.5 ms
64 bytes from 192.168.77.1: icmp_req=66 ttl=64 time=54.7 ms
64 bytes from 192.168.77.1: icmp_req=67 ttl=64 time=75.1 ms
64 bytes from 192.168.77.1: icmp_req=68 ttl=64 time=6.47 ms
64 bytes from 192.168.77.1: icmp_req=69 ttl=64 time=28.7 ms
64 bytes from 192.168.77.1: icmp_req=70 ttl=64 time=153 ms
64 bytes from 192.168.77.1: icmp_req=71 ttl=64 time=177 ms
64 bytes from 192.168.77.1: icmp_req=72 ttl=64 time=200 ms
64 bytes from 192.168.77.1: icmp_req=73 ttl=64 time=223 ms
64 bytes from 192.168.77.1: icmp_req=74 ttl=64 time=246 ms
64 bytes from 192.168.77.1: icmp_req=75 ttl=64 time=269 ms
64 bytes from 192.168.77.1: icmp_req=76 ttl=64 time=292 ms
64 bytes from 192.168.77.1: icmp_req=77 ttl=64 time=315 ms
64 bytes from 192.168.77.1: icmp_req=78 ttl=64 time=338 ms
64 bytes from 192.168.77.1: icmp_req=79 ttl=64 time=361 ms
64 bytes from 192.168.77.1: icmp_req=80 ttl=64 time=384 ms
64 bytes from 192.168.77.1: icmp_req=81 ttl=64 time=407 ms
64 bytes from 192.168.77.1: icmp_req=82 ttl=64 time=431 ms
64 bytes from 192.168.77.1: icmp_req=83 ttl=64 time=557 ms
64 bytes from 192.168.77.1: icmp_req=84 ttl=64 time=581 ms
64 bytes from 192.168.77.1: icmp_req=85 ttl=64 time=604 ms
64 bytes from 192.168.77.1: icmp_req=86 ttl=64 time=627 ms
64 bytes from 192.168.77.1: icmp_req=87 ttl=64 time=650 ms
64 bytes from 192.168.77.1: icmp_req=88 ttl=64 time=674 ms
64 bytes from 192.168.77.1: icmp_req=89 ttl=64 time=699 ms
64 bytes from 192.168.77.1: icmp_req=90 ttl=64 time=722 ms
64 bytes from 192.168.77.1: icmp_req=91 ttl=64 time=746 ms
64 bytes from 192.168.77.1: icmp_req=92 ttl=64 time=771 ms
64 bytes from 192.168.77.1: icmp_req=93 ttl=64 time=797 ms
64 bytes from 192.168.77.1: icmp_req=94 ttl=64 time=822 ms
64 bytes from 192.168.77.1: icmp_req=95 ttl=64 time=847 ms
64 bytes from 192.168.77.1: icmp_req=96 ttl=64 time=872 ms
64 bytes from 192.168.77.1: icmp_req=97 ttl=64 time=897 ms
64 bytes from 192.168.77.1: icmp_req=98 ttl=64 time=1024 ms
64 bytes from 192.168.77.1: icmp_req=99 ttl=64 time=18.4 ms
64 bytes from 192.168.77.1: icmp_req=100 ttl=64 time=41.2 ms
64 bytes from 192.168.77.1: icmp_req=101 ttl=64 time=64.3 ms
64 bytes from 192.168.77.1: icmp_req=102 ttl=64 time=87.3 ms
64 bytes from 192.168.77.1: icmp_req=103 ttl=64 time=110 ms
64 bytes from 192.168.77.1: icmp_req=104 ttl=64 time=133 ms
64 bytes from 192.168.77.1: icmp_req=105 ttl=64 time=156 ms
64 bytes from 192.168.77.1: icmp_req=106 ttl=64 time=179 ms
64 bytes from 192.168.77.1: icmp_req=107 ttl=64 time=202 ms
64 bytes from 192.168.77.1: icmp_req=108 ttl=64 time=225 ms
64 bytes from 192.168.77.1: icmp_req=109 ttl=64 time=350 ms
64 bytes from 192.168.77.1: icmp_req=110 ttl=64 time=374 ms
64 bytes from 192.168.77.1: icmp_req=111 ttl=64 time=397 ms
64 bytes from 192.168.77.1: icmp_req=112 ttl=64 time=420 ms
64 bytes from 192.168.77.1: icmp_req=113 ttl=64 time=443 ms
64 bytes from 192.168.77.1: icmp_req=114 ttl=64 time=1491 ms
64 bytes from 192.168.77.1: icmp_req=115 ttl=64 time=491 ms
64 bytes from 192.168.77.1: icmp_req=116 ttl=64 time=514 ms
64 bytes from 192.168.77.1: icmp_req=117 ttl=64 time=538 ms
64 bytes from 192.168.77.1: icmp_req=118 ttl=64 time=562 ms
64 bytes from 192.168.77.1: icmp_req=119 ttl=64 time=585 ms
64 bytes from 192.168.77.1: icmp_req=120 ttl=64 time=608 ms
64 bytes from 192.168.77.1: icmp_req=121 ttl=64 time=632 ms
64 bytes from 192.168.77.1: icmp_req=122 ttl=64 time=655 ms
64 bytes from 192.168.77.1: icmp_req=123 ttl=64 time=679 ms
64 bytes from 192.168.77.1: icmp_req=124 ttl=64 time=703 ms
64 bytes from 192.168.77.1: icmp_req=125 ttl=64 time=728 ms
64 bytes from 192.168.77.1: icmp_req=126 ttl=64 time=752 ms
64 bytes from 192.168.77.1: icmp_req=127 ttl=64 time=1803 ms
64 bytes from 192.168.77.1: icmp_req=128 ttl=64 time=803 ms
64 bytes from 192.168.77.1: icmp_req=129 ttl=64 time=826 ms
64 bytes from 192.168.77.1: icmp_req=130 ttl=64 time=954 ms
64 bytes from 192.168.77.1: icmp_req=131 ttl=64 time=981 ms
64 bytes from 192.168.77.1: icmp_req=132 ttl=64 time=1004 ms
64 bytes from 192.168.77.1: icmp_req=133 ttl=64 time=0.924 ms
64 bytes from 192.168.77.1: icmp_req=134 ttl=64 time=25.5 ms
64 bytes from 192.168.77.1: icmp_req=135 ttl=64 time=46.2 ms
64 bytes from 192.168.77.1: icmp_req=136 ttl=64 time=172 ms

TheWiFiGuy · Fri Jun 29, 2012 5:42 pm

Not enough info.

What revision firmare? Just a single AP, not routing or bridging loops? Clients signal strength?

Whats the Log saying?

rotten777 · Fri Jun 29, 2012 7:23 pm

Not enough info.

What revision firmare? Just a single AP, not routing or bridging loops? Clients signal strength?

Whats the Log saying?

fw is 2.39
ros is 5.18
this is a single soho router setup. ether1 is wan, 2 is lan with dhcp, wlan1 is wireless. very basic. signal strength doesn't matter. i was 6 feet from the router troubleshooting when i got that ping response i posted.

rotten777 · Fri Jun 29, 2012 7:29 pm

this is the only thing I can find in the log that isn't normal auth/deauth

echo: wireless,info C8:AA:21:40:02:C5@wlan1: disconnected, group key exchange timeout

rotten777 · Fri Jun 29, 2012 8:01 pm

I set the group key update to 1 hour. It seems to have stabilized. But I'm assuming at the 1 hour point, whatever is screwed up with knock all wireless clients off.

TheWiFiGuy · Fri Jun 29, 2012 10:27 pm

Try dropping the power down to circa 23db , by default its 30db which is way to high.

Also, just for a test, try without using WPA/WPA2 and see if the ping response stabilises.

matt · Fri Jun 29, 2012 11:49 pm

Hi Mr Rotten777

I have been using MikroTik for over 8 years myself with hundreds of installations.

Yesterday I installed a RB/711UA-2HnD and it sounds like I had the same problem with the group-key fault in the log file.

The signal strengths are in the -60's. 5 x Clients, all of the TX rates were 1Mbps but the Rx rates are 180Mbps etc.

I used an M2 Loco to connected and I had a lot of trouble getting it to connect. In the end I changed the security on the M2 Loco to WPA2 only, with out the TKIP as it had chosen when I scanned and selected as I have normally done over the years.

The interesting thing was it thought the radio was 42km away, but is only 1.2km. It did show 1.2km when first booted up, but the AP faults very quickly.

I spent a couple of hours wasting my time upgrading to latest OS 5.18 and upgrade firmware.

I do not have remote access, so when I return, I will take RB411U and R52Hn to replace as I can not afford to spend my time fault finding something silly like this fault.

The only thing I have not done is a system reset and reconfigure.

I normally use 5GHz radios for my WISP and have not used the 2.4GHz radio board mentioned above, so this is the first time I have used it as it for a network over a farm.

I would appreciate any feedback to others can duplicate this fault and resolve it.

Cheers

lordkappa · Sat Jun 30, 2012 3:32 am

I have the same problem Matt does with my 751u-2hnd. It's an intermittent problem where the TX rates will drop to abysmal levels, (1-10mbps) stay there for some period of time (Between 1 and 10 minutes) then eventually rise back to normal rates.

It happens with all clients, on any combination of settings. I've tried WPA, WPA2, WEP, different channels/width, different antennae chains, WMM on/off, advanced/legacy rate selection and b/g/n | n-only | g-only | b-only. Nothing alleviates the problem.

It seems to me that it's a problem with the rate selection, as during the problem the signal strength and/or error rate never changes. Strangely, my AP also thinks the clients are over 1km away, even when they're in the same room.

Support-out is available.

Currently I am running: AP Bridge, 2ghz-b/g/n, 2412mhz, 40mhz HT Above, WPA2-PSK AES CCM.

jandafields · Sat Jun 30, 2012 5:47 am

Yes, common problem. If everyone will send this to support@mikrotik.com with supout... perhaps they can find the issue quicker.

matt · Sat Jun 30, 2012 7:30 am

Hi Jandafields

I sent a support file today.

I use the RB711 integrated 5GHz radios and just starting to play with 2.4GHz, I have not had this issue with any of the 5GHz radios.

What hardware devices do you know of that have this problem?

Cheers

TheWiFiGuy · Sat Jun 30, 2012 10:35 pm

1km distance is the smallest distance the system can report based on the calculations it uses, and is nothing to worry about.

No ones still posted their signal strength and tx power outputs.

matt · Sat Jun 30, 2012 11:11 pm

The link distance is 1.2km
Registration Signal says it is 20kms.

Signal strength -62/-66
Tx 2Mbps / Rx 180Mbps
Signal to Noise 48dB
CCQ 10/99%
P Throughput 530kbps

Here is an export compact:

[blabla@AP] > export compact
# jan/02/1970 18:40:24 by RouterOS 5.18
# software id = TGIT-QIB0
#
/interface bridge
add l2mtu=1598 name=bridge1 protocol-mode=rstp
/interface wireless
set 0 band=2ghz-b/g/n channel-width=20/40mhz-ht-above disabled=no frequency=2437 ht-rxchains=0,1 ht-txchains=0,1 l2mtu=\
2290 mode=ap-bridge rate-selection=legacy rate-set=configured ssid="ACCESS POINT" supported-rates-a/g=6Mbps,9Mbps \
wds-default-bridge=bridge1 wds-mode=dynamic wireless-protocol=802.11
/interface wireless security-profiles
set [ find default=yes ] authentication-types=wpa2-psk group-ciphers=tkip,aes-ccm mode=dynamic-keys supplicant-identity=\
MikroTik unicast-ciphers=tkip,aes-ccm wpa-pre-shared-key=k0lm4rf4rm wpa2-pre-shared-key=securitykey
/ip dhcp-server
add interface=ether1 name=dhcp1
add interface=bridge1 name=dhcp2
/ip hotspot user profile
set [ find default=yes ] idle-timeout=none keepalive-timeout=2m
/interface bridge port
add bridge=bridge1 interface=ether1
add bridge=bridge1 interface=wlan1
/ip address
add address=10.25.0.3/24 interface=wlan1
/ip dns
set servers=202.37.101.1,202.37.101.2
/ip neighbor discovery
set wlan1 disabled=yes
/ip route
add distance=1 gateway=10.25.0.1
/system identity
set name="Kolmar Farm AP"
/system leds
set 0 interface=wlan1
/system logging
add topics=wireless
[bla@AP] >

Is this only being seen on the RB751U-2HnD?

matt · Sat Jun 30, 2012 11:22 pm

Here is a visual:

RB711UA-2HnD Radio.JPG

lordkappa · Sun Jul 01, 2012 5:42 am

Likewise. I have also sent this file to support along with my supout.

rotten777 · Tue Jul 03, 2012 1:06 am

Try dropping the power down to circa 23db , by default its 30db which is way to high.

Also, just for a test, try without using WPA/WPA2 and see if the ping response stabilises.

I removed encryption. I will change the power output once I get home and try it again and I will let you know the outcome.

rotten777 · Tue Jul 03, 2012 5:22 am

here's the current power tx

tx power mode is card rates and it's at 30 right now. doesn't seem to change the actual output. i must be missing something.

scampbell · Fri Jul 06, 2012 7:59 pm

The link distance is 1.2km
Registration Signal says it is 20kms.

Signal strength -62/-66
Tx 2Mbps / Rx 180Mbps
Signal to Noise 48dB
CCQ 10/99%
P Throughput 530kbps

/interface wireless security-profiles
set [ find default=yes ] authentication-types=wpa2-psk group-ciphers=tkip,aes-ccm mode=dynamic-keys supplicant-identity=\
MikroTik unicast-ciphers=tkip,aes-ccm wpa-pre-shared-key=k0lm4rf4rm wpa2-pre-shared-key=securitykey
..........

Is this only being seen on the RB751U-2HnD?

Be sure to disable TKIP in your WPA/WPA2 profiles.

Also try changing TX Power by using the "card rates" option to say 17dbm

I have found that being to close to the AP with high power does not work well.

matt · Fri Jul 06, 2012 10:38 pm

Hi Guys

I upgraded to a RB711 with R52Hn, this reduced the signal strength 1km away. Default TX.

I changed the security to aes and disabled TKIP, this has stopped the "wlan1: disconnected, group key exchange timeout" issue.

Pinging the client radio every 100 ms gives me this CCQ: 106/99 %

P Throughput: 28498 kbps

Thank y0u for your help guys, "not using TKIP for security" seamed to be the issue.