topic Re: Decrypt Errors with WPA2 in Wireless

Decrypt Errors with WPA2

MICHAEL SCHROEDER — Sun, 04 Jul 2021 00:23:07 GMT

Hi All, i see a lot of Messages in my Traplog: "Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]". Does anyone know what this means? We are using WPA2 with AES exclusively, no legacy Clients, all are 4965AGN with latest Proset. Thx and rgrds, Michael

Re: Decrypt Errors with WPA2

Leo Laohoo — Mon, 30 Mar 2009 22:13:59 GMT

As long as the clients don't get disconnected, I believe this could be a bug. What's your firmware?

Re: Decrypt Errors with WPA2

MICHAEL SCHROEDER — Tue, 31 Mar 2009 06:56:53 GMT

Hi, the Controllers are running on 4.2.176.0

Re: Decrypt Errors with WPA2

MICHAEL SCHROEDER — Tue, 31 Mar 2009 10:35:50 GMT

Additionally, these Error occurs frequently every 2 minutes, as the Traplog shows:

48 Tue Mar 31 11:11:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

49 Tue Mar 31 11:09:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

50 Tue Mar 31 11:07:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

52 Tue Mar 31 11:05:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

53 Tue Mar 31 11:03:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

54 Tue Mar 31 11:01:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

55 Tue Mar 31 10:59:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

56 Tue Mar 31 10:57:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

57 Tue Mar 31 10:55:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

58 Tue Mar 31 10:53:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

59 Tue Mar 31 10:51:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

60 Tue Mar 31 10:49:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

61 Tue Mar 31 10:47:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

62 Tue Mar 31 10:45:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

63 Tue Mar 31 10:43:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

64 Tue Mar 31 10:41:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

65 Tue Mar 31 10:39:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

66 Tue Mar 31 10:37:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

67 Tue Mar 31 10:35:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

68 Tue Mar 31 10:33:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

69 Tue Mar 31 10:31:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

70 Tue Mar 31 10:29:22 2009 Decrypt errors occurred for client [MAC] using WPA2 key on 802.11a interface of AP [MAC]

Regards, Michael

Re: Decrypt Errors with WPA2

Leo Laohoo — Tue, 31 Mar 2009 22:49:17 GMT

Hi Michael,

If you want to disable this trap logs, go to Management -> SNMP -> Trap Controls -> Security. Untick "WEP Decrypt Error".

Hope this helps.

Re: Decrypt Errors with WPA2

MICHAEL SCHROEDER — Wed, 01 Apr 2009 06:05:04 GMT

Hi Leo, yeah, did this yesterday, since them the Problem is solved ;-))

But what does this Error mean? Is this something that happens during Security Capability Negitiation? Thx and Regards, Michael

Re: Decrypt Errors with WPA2

Leo Laohoo — Wed, 01 Apr 2009 21:44:56 GMT

Hi Michael,

Good to hear. This error, and I'm just guessing here, is possibly caused by the "incompatibility" of the client's Wireless NIC card to the Cisco codec.

Is this happening to only one client or a number of clients?

Are they using a particular wireless NIC card or are they using a mix set?

When these clients are authenticated on the Wireless LAN, do they get dropouts?

If you go to Monitor -> Clients and then drill down to the client, under Security Information, what is the output?