Multiple problems with "deauth" spam/DOS
Posted: Tue Apr 10, 2007 9:12 pm
I'm having a strange issue with the "deauth" spam a few other forum users have posted about. I haven't seen any real explanation or possible solution in the community forum regarding this issue though, there are a couple of recent threads:
http://forum.mikrotik.com/viewtopic.php ... ght=deauth
http://forum.mikrotik.com/viewtopic.php ... ght=deauth
http://forum.mikrotik.com/viewtopic.php ... ght=deauth
http://forum.mikrotik.com/viewtopic.php ... ght=deauth
This has now happened on 3 AP's in the span of less than a week, when we've never seen it before.
The first AP is an RB532 w/ 502 daughter board, SR2 in AP mode, R52 in client mode, and Prism 2511MP in client mode. This access point has been up and running for about 1.5 years. At some point, all stations disassociated for some unknown reason, and the log began filling with error messages like this:
I worked extensively with the configuration (including changing ROS versions from 2.9.38 to 2.9.42, and even 2.9.27) trying to resolve the problem (adjusting various settings), and was able to get a few stations to associate. Notably all were Atheros stations, no Prism (CB3) stations would associate. Eventually, I gave up as it was late at night. The next morning, everybody was associated. Here is the log excerpt from when everything came back (pppoe entries removed):
I suspect that the problem may be CPE related, and in this case possibly cleared up when the CPE was rebooted (i.e. someone trying to use their service, restarted CPE because it wasn't working). About 12 hours later, I was monitoring the situation and decided to change the AP from 2.4Ghz-B where it had settled in while troubleshooting, back to 2.4Ghz-B/G. When I changed it, the *exact* same thing happened again, with even the same MAC addresses showing up in the deauth logs. Again, I messed with it and ended up leaving the thing alone. The next morning, everybody was back again.
Our initial thought was that perhaps this was a damaged SR2 or something of that nature, especially since I tried several different revisions of ROS in the troubleshooting process. However, the following Monday (yesterday) I had the same situation come up on another AP some distance away (about 80 miles). This AP has been acting strangely for a while, but I can't say if it's been this issue or not.
The second AP is an RB532+502, running 2.9.38 with an SR2, SR5 (output power lowered), and 2x 2511MP, one set to 8dB output power to go easier on the PSU. I feel that previous issues with this AP are due to overload on the RB532 power supply, but in this situation I saw exactly the same symptoms as the first AP I talked about.
I tried many configuration changes, including updating ROS to 2.9.42. I did not try older versions on this unit because it didn't make a difference on the first one. After trying quite a few settings and not bringing stations back, I left it alone for about 4 to 6 hours. The stations did not return. As a last ditch effort, I had the thought that if the stations that are de-authing think they are associated, but the AP doesn't, what if the AP changed? To this end, I changed the MAC address of the AP. Immediately, all stations re-associated and have remained associated since that time.
The 3rd AP did the same thing, though when I changed the MAC address, it didn't seem to help immidiatly. I changed it back, and diddled a little more, then all of the stations came back. I don't know for sure, but I feel like changing the MAC and changing it back may have been the catalyst to resolution.
Is it possible that the CPE is the issue? In all cases the most log entries for the deauth issue show as EZ3+ MAC addresses (http://www.e-zy.net/products/outdoor/3plus), though some LS2 MAC id's showed up. No prisms exhibited this issue. We don't have very many of these units, because we were not happy with the high failure rate.
I sincerely doubt that it could be bad hardware, as the same issue has occurred on 3 separate AP units. In some cases on these forums, users reported that changing the card resolved the problem, but it seems to me like that may have been resolution because the MAC ID changed, not because the card was bad. In these situations, I have to wonder what would have happened if they simply changed the MAC ID instead of changing the hardware.
Any thoughts or input on this subject are appreciated! I've also submitted a ticket to the official support channels including supout files, but I was hoping to perhaps get some more input from the community.
http://forum.mikrotik.com/viewtopic.php ... ght=deauth
http://forum.mikrotik.com/viewtopic.php ... ght=deauth
http://forum.mikrotik.com/viewtopic.php ... ght=deauth
http://forum.mikrotik.com/viewtopic.php ... ght=deauth
This has now happened on 3 AP's in the span of less than a week, when we've never seen it before.
The first AP is an RB532 w/ 502 daughter board, SR2 in AP mode, R52 in client mode, and Prism 2511MP in client mode. This access point has been up and running for about 1.5 years. At some point, all stations disassociated for some unknown reason, and the log began filling with error messages like this:
Code: Select all
05:20:55 wireless,info Broadcast: data from unknown device 00:11:7C:0A:12:CC, sent deauth (1 events suppressed)
05:20:59 wireless,info Broadcast: data from unknown device 00:11:7C:0A:12:E0, sent deauth (1 events suppressed)
05:21:04 wireless,info Broadcast: data from unknown device 00:11:7C:0A:12:E0, sent deauth (13 events suppressed, 3 deauths suppressed)
05:21:10 wireless,info Broadcast: data from unknown device 00:11:7C:0A:12:E0, sent deauth (4 events suppressed)
05:21:15 wireless,info Broadcast: data from unknown device 00:11:7C:0A:12:E0, sent deauth (2 events suppressed)
05:21:20 wireless,info Broadcast: data from unknown device 00:11:7C:0A:12:E0, sent deauth (2 events suppressed)
05:21:25 wireless,info Broadcast: data from unknown device 00:11:7C:0A:12:E0, sent deauth
05:21:30 wireless,info Broadcast: data from unknown device 00:11:7C:0A:12:E0, sent deauth
05:21:35 wireless,info Broadcast: data from unknown device 00:11:7C:0A:12:E0, sent deauth
05:21:41 wireless,info Broadcast: data from unknown device 00:11:7C:0A:12:CC, sent deauth (1 events suppressed)
Code: Select all
05:26:55 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth
05:27:00 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (7 events suppressed)
05:27:03 wireless,info Broadcast: data from unknown device 00:11:7C:0A:12:E0, sent deauth (2 events suppressed)
05:27:10 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (2 events suppressed)
05:27:12 wireless,info 00:11:7C:0A:12:E0@Broadcast: connected
05:27:15 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:16 wireless,info 00:11:7C:0A:12:E0@Broadcast: disconnected, reassociating
05:27:20 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:24 wireless,info 00:11:7C:0A:12:E0@Broadcast: connected
05:27:25 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:31 wireless,info 00:11:7C:0A:12:CC@Broadcast: connected
05:27:36 wireless,info 00:11:7C:0A:10:EC@Broadcast: connected
05:27:38 wireless,info 00:02:6F:3F:1F:BC@Broadcast: connected
05:27:39 wireless,info 00:02:6F:3B:F0:9D@Broadcast: connected
05:27:41 wireless,info 00:02:6F:41:5D:92@Broadcast: connected
05:27:41 wireless,info 00:02:6F:3A:DF:E4@Broadcast: connected
05:27:15 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:16 wireless,info 00:11:7C:0A:12:E0@Broadcast: disconnected, reassociating
05:27:20 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:24 wireless,info 00:11:7C:0A:12:E0@Broadcast: connected
05:27:25 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:31 wireless,info 00:11:7C:0A:12:CC@Broadcast: connected
05:27:36 wireless,info 00:11:7C:0A:10:EC@Broadcast: connected
05:27:38 wireless,info 00:02:6F:3F:1F:BC@Broadcast: connected
05:27:39 wireless,info 00:02:6F:3B:F0:9D@Broadcast: connected
05:27:41 wireless,info 00:02:6F:41:5D:92@Broadcast: connected
05:27:41 wireless,info 00:02:6F:3A:DF:E4@Broadcast: connected
05:27:15 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:16 wireless,info 00:11:7C:0A:12:E0@Broadcast: disconnected, reassociating
05:27:20 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:24 wireless,info 00:11:7C:0A:12:E0@Broadcast: connected
05:27:25 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:31 wireless,info 00:11:7C:0A:12:CC@Broadcast: connected
05:27:36 wireless,info 00:11:7C:0A:10:EC@Broadcast: connected
05:27:38 wireless,info 00:02:6F:3F:1F:BC@Broadcast: connected
05:27:39 wireless,info 00:02:6F:3B:F0:9D@Broadcast: connected
05:27:41 wireless,info 00:02:6F:41:5D:92@Broadcast: connected
05:27:41 wireless,info 00:02:6F:3A:DF:E4@Broadcast: connected
05:27:15 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:16 wireless,info 00:11:7C:0A:12:E0@Broadcast: disconnected, reassociating
05:27:20 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:24 wireless,info 00:11:7C:0A:12:E0@Broadcast: connected
05:27:25 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:31 wireless,info 00:11:7C:0A:12:CC@Broadcast: connected
05:27:36 wireless,info 00:11:7C:0A:10:EC@Broadcast: connected
05:27:38 wireless,info 00:02:6F:3F:1F:BC@Broadcast: connected
05:27:39 wireless,info 00:02:6F:3B:F0:9D@Broadcast: connected
05:27:41 wireless,info 00:02:6F:41:5D:92@Broadcast: connected
05:27:41 wireless,info 00:02:6F:3A:DF:E4@Broadcast: connected
05:27:15 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:16 wireless,info 00:11:7C:0A:12:E0@Broadcast: disconnected, reassociating
05:27:20 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:24 wireless,info 00:11:7C:0A:12:E0@Broadcast: connected
05:27:25 wireless,info Broadcast: data from unknown device 00:11:7C:0A:10:EC, sent deauth (1 events suppressed)
05:27:31 wireless,info 00:11:7C:0A:12:CC@Broadcast: connected
05:27:36 wireless,info 00:11:7C:0A:10:EC@Broadcast: connected
05:27:38 wireless,info 00:02:6F:3F:1F:BC@Broadcast: connected
05:27:39 wireless,info 00:02:6F:3B:F0:9D@Broadcast: connected
05:27:41 wireless,info 00:02:6F:41:5D:92@Broadcast: connected
05:27:41 wireless,info 00:02:6F:3A:DF:E4@Broadcast: connected
05:27:41 wireless,info 00:02:6F:3F:1E:E5@Broadcast: connected
05:27:41 wireless,info 00:02:6F:3A:D6:8E@Broadcast: connected
05:27:42 wireless,info 00:02:6F:3F:1F:BC@Broadcast: disconnected, reassociating
05:27:42 wireless,info 00:02:6F:3F:1F:BC@Broadcast: connected
05:27:43 wireless,info 00:02:6F:3F:21:05@Broadcast: connected
05:27:43 wireless,info 00:02:6F:3B:E7:56@Broadcast: connected
05:27:44 wireless,info 00:02:6F:44:C5:22@Broadcast: connected
05:27:46 wireless,info 00:02:6F:3A:D4:9F@Broadcast: connected
05:27:46 wireless,info 00:02:6F:3B:EA:5F@Broadcast: connected
05:27:46 wireless,info 00:02:6F:3A:D4:A0@Broadcast: connected
05:27:47 wireless,info 00:02:6F:3A:E2:F9@Broadcast: connected
05:27:47 wireless,info 00:02:6F:41:50:2E@Broadcast: connected
05:27:48 wireless,info 00:02:6F:3B:EA:71@Broadcast: connected
05:27:49 wireless,info 00:02:6F:3A:E0:74@Broadcast: connected
05:27:50 wireless,info 00:02:6F:3B:ED:2F@Broadcast: connected
05:27:50 wireless,info 00:02:6F:3A:D5:E6@Broadcast: connected
05:27:50 wireless,info 00:02:6F:3F:1F:89@Broadcast: connected
05:27:50 wireless,info 00:02:6F:3B:ED:30@Broadcast: connected
05:27:51 wireless,info 00:02:6F:3B:F0:96@Broadcast: connected
05:27:52 wireless,info 00:02:6F:3D:74:8C@Broadcast: connected
05:27:53 wireless,info 00:02:6F:3B:EF:90@Broadcast: connected
05:27:53 wireless,info 00:02:6F:38:56:7F@Broadcast: connected
05:27:53 wireless,info 00:02:6F:3A:88:F0@Broadcast: connected
05:28:06 wireless,info 00:02:6F:3B:E7:E0@Broadcast: connected
05:28:57 wireless,info 00:02:6F:3A:DF:E7@Broadcast: connected
Our initial thought was that perhaps this was a damaged SR2 or something of that nature, especially since I tried several different revisions of ROS in the troubleshooting process. However, the following Monday (yesterday) I had the same situation come up on another AP some distance away (about 80 miles). This AP has been acting strangely for a while, but I can't say if it's been this issue or not.
The second AP is an RB532+502, running 2.9.38 with an SR2, SR5 (output power lowered), and 2x 2511MP, one set to 8dB output power to go easier on the PSU. I feel that previous issues with this AP are due to overload on the RB532 power supply, but in this situation I saw exactly the same symptoms as the first AP I talked about.
I tried many configuration changes, including updating ROS to 2.9.42. I did not try older versions on this unit because it didn't make a difference on the first one. After trying quite a few settings and not bringing stations back, I left it alone for about 4 to 6 hours. The stations did not return. As a last ditch effort, I had the thought that if the stations that are de-authing think they are associated, but the AP doesn't, what if the AP changed? To this end, I changed the MAC address of the AP. Immediately, all stations re-associated and have remained associated since that time.
The 3rd AP did the same thing, though when I changed the MAC address, it didn't seem to help immidiatly. I changed it back, and diddled a little more, then all of the stations came back. I don't know for sure, but I feel like changing the MAC and changing it back may have been the catalyst to resolution.
Is it possible that the CPE is the issue? In all cases the most log entries for the deauth issue show as EZ3+ MAC addresses (http://www.e-zy.net/products/outdoor/3plus), though some LS2 MAC id's showed up. No prisms exhibited this issue. We don't have very many of these units, because we were not happy with the high failure rate.
I sincerely doubt that it could be bad hardware, as the same issue has occurred on 3 separate AP units. In some cases on these forums, users reported that changing the card resolved the problem, but it seems to me like that may have been resolution because the MAC ID changed, not because the card was bad. In these situations, I have to wonder what would have happened if they simply changed the MAC ID instead of changing the hardware.
Any thoughts or input on this subject are appreciated! I've also submitted a ticket to the official support channels including supout files, but I was hoping to perhaps get some more input from the community.