Intermittent dropouts Intel Centrino Advanced-N 6205

[chris.brunt]

We are having big problems just with this particular adapter in our environment. We are getting intermittent dropouts. The connection will freeze and stop responding to the point where you have to do a windows repair or restart the adapter to get it working again. You can be connected for a whole day with no issues or it could happen at random eg after 20 mins of being connected. Other devices in close proximity e.g. an intel 5100 and 5300 agn are working perfectly.

You get no indication that the connection has dropped and the adapter in the systray looks as if it is still transmitting packets but not recieving any. Cisco WCS troubleshoot indicates no problems. Events in the debug stop and dont start again until you do a repair on the machine.

Intel and Lenovo support have been really unhelpful (they basically don't want to know, apalling service), so now i am turning to Cisco just in case its a configuration issue, which i don't believe it is as we have no reported issues at all with other clients.

On the machine sides we have:

Lenovo x220 Tablet with Intel Centrino Advanced-N 6205 mini pci-e adapter.

Also happening with Fujitsu T730 tablets also with with Intel Centrino Advanced-N 6205 mini pci-e adapters

We have tried all intel driver versions from the latest 14.2.0.10 down to the OEM versions supplied.

they are running Windows XP SP3. We have also tried it with Windows 7 and get similar issues.

We are using Windows Wireless Zero Configuration, WPA2-AES with PEAP and machine (computer) authentication against Cisco ACS v5.2 talking to AD.

On the Wireless infrastructure side we have:

Cisco 1142N (-E-K9) APs connected to 3750G w/poe stacks

The controller is a 3750G-24-WS-50 model running version 7.0.116.0

managed by WCS.

The wireless has 20mhz channels on 1,6,11 on the 2.4ghz side (N is disabled) but we do have N enabled with 40mhz channels on the 5ghz with all UK country channels.

The machines connect at up to 300mb/s and signal quality is excellent. AP density is quite high in the room. DCA, TPC and Tx power control are enabled and set to automatic.

Can't think of more detail to include but I would appreciate any ideas anyone may have.

[Stephen Rodriguez]

Are you able to do a wireless sniffer trace to see if the client is truly not sending data, or the ap is just dropping it?

Sent from Cisco Technical Support iPhone App

[chris.brunt]

With wireshark i can see packets going to the adapter but they get no response.

[Scott Fella]

So it only happens with this wlan ssid?  Can you post the show wlan

[chris.brunt]

(Cisco Controller) >show wlan 5

WLAN Identifier.................................. 5

Profile Name..................................... SSID vlan 6

Network Name (SSID).............................. SSID

Status........................................... Enabled

MAC Filtering.................................... Disabled

Broadcast SSID................................... Enabled

AAA Policy Override.............................. Disabled

Network Admission Control

  Radius-NAC State............................... Disabled

  SNMP-NAC State................................. Disabled

  Quarantine VLAN................................ 0

Maximum number of Associated Clients............. 0

Number of Active Clients......................... 1

Exclusionlist.................................... Disabled

Session Timeout.................................. Infinity

CHD per WLAN..................................... Enabled

Webauth DHCP exclusion........................... Disabled

Interface........................................ vlan6

Multicast Interface.............................. Not Configured

WLAN ACL......................................... unconfigured

DHCP Server...................................... Default

DHCP Address Assignment Required................. Disabled

Static IP client tunneling....................... Disabled

Quality of Service............................... Silver (best effort)

Scan Defer Priority.............................. 4,5,6

Scan Defer Time.................................. 100 milliseconds

WMM.............................................. Allowed

WMM UAPSD Compliant Client Support............... Disabled

Media Stream Multicast-direct.................... Disabled

CCX - AironetIe Support.......................... Enabled

CCX - Gratuitous ProbeResponse (GPR)............. Disabled

CCX - Diagnostics Channel Capability............. Disabled

Dot11-Phone Mode (7920).......................... Disabled

Wired Protocol................................... None

IPv6 Support..................................... Disabled

Peer-to-Peer Blocking Action..................... Disabled

Radio Policy..................................... All

DTIM period for 802.11a radio.................... 1

DTIM period for 802.11b radio.................... 1

Radius Servers

   Authentication................................ 192.168.1.170 1812

   Authentication................................ 192.168.14.7 1812

   Accounting.................................... 192.168.1.170 1813

   Accounting.................................... 192.168.14.7 1813

   Dynamic Interface............................. Disabled

Local EAP Authentication......................... Disabled

Security

   802.11 Authentication:........................ Open System

   Static WEP Keys............................... Disabled

   802.1X........................................ Disabled

   Wi-Fi Protected Access (WPA/WPA2)............. Enabled

      WPA (SSN IE)............................... Disabled

      WPA2 (RSN IE).............................. Enabled

         TKIP Cipher............................. Disabled

         AES Cipher.............................. Enabled

                                                               Auth Key Management

         802.1x.................................. Enabled

         PSK..................................... Disabled

         CCKM.................................... Disabled

         FT(802.11r)............................. Disabled

         FT-PSK(802.11r)......................... Disabled

FT Reassociation Timeout......................... 20

FT Over-The-Air mode............................. Enabled

FT Over-The-Ds mode.............................. Enabled

CCKM tsf Tolerance............................... 1000

   CKIP ......................................... Disabled

   IP Security................................... Disabled

   IP Security Passthru.......................... Disabled

   Web Based Authentication...................... Disabled

   Web-Passthrough............................... Disabled

   Conditional Web Redirect...................... Disabled

   Splash-Page Web Redirect...................... Disabled

   Auto Anchor................................... Disabled

   H-REAP Local Switching........................ Disabled

   H-REAP Local Authentication................... Disabled

   H-REAP Learn IP Address....................... Enabled

   Client MFP.................................... Optional

   Tkip MIC Countermeasure Hold-down Timer....... 60

Call Snooping.................................... Disabled

Roamed Call Re-Anchor Policy..................... Disabled

SIP CAC Fail Send-486-Busy Policy................ Enabled

SIP CAC Fail Send Dis-Association Policy......... Disabled

Band Select...................................... Enabled

Load Balancing................................... Enabled

Mobility Anchor List

WLAN ID     IP Address            Status

[Scott Fella]

Disable the client load balancing and band select.  If that fixes your issue then try to enable band select, but don't enable load balancing.  Leave both off for a couple days and then try to enable band select only...... If you have issue with band select, then you know that you have to disable that too.

[chris.brunt]

Thanks for the suggestion. I will give that a go on monday and report back.

[Scott Fella]

That load balancing had caused me headaches! Many of the Apple devices will not connect with this enabled also.

Thanks,

Scott Fella

Sent from my iPhone

[cwiuser01]

I have the exact same scenario with the AD/ACS authentication and using WLC and WCS to manage the wirleless network.  The problem only occurs with the newer Intel Centrino Advanced-N 6205 as the bit older Advanced 6200-N does not have the problems.

My current configuration for the two SSID's that the client attaches to does not have the Client load balancing or band select enabled.

Any success with your changes?

[chris.brunt]

I am waiting for feedback on the changes (disabled load balancing and band select on monday) at the moment.

[mike.willing]

I've been have this exact issue with the following infrastructure:

Cisco 5508 running 7.1.91.0

Cisco 3602i (A)

Here is my current configuration.

(Cisco Controller) >show wlan 20                                             

WLAN Identifier.................................. 20

Profile Name..................................... Data_Laptop_Devices

Network Name (SSID).............................. wland1

Status........................................... Enabled

MAC Filtering.................................... Disabled

Broadcast SSID................................... Disabled

AAA Policy Override.............................. Disabled

Network Admission Control

  Radius-NAC State............................... Disabled

  SNMP-NAC State................................. Disabled

  Quarantine VLAN................................ 0

Maximum number of Associated Clients............. 0

Number of Active Clients......................... 1

Exclusionlist Timeout............................ 60 seconds

Session Timeout.................................. 86400 seconds

CHD per WLAN..................................... Enabled

Webauth DHCP exclusion........................... Disabled

Interface........................................ management

Multicast Interface.............................. Not Configured

WLAN ACL......................................... unconfigured

DHCP Server...................................... Default

DHCP Address Assignment Required................. Disabled

Static IP client tunneling....................... Disabled

Quality of Service............................... Silver (best effort)

Scan Defer Priority.............................. 5,6

Scan Defer Time.................................. 100 milliseconds

WMM.............................................. Allowed

WMM UAPSD Compliant Client Support............... Disabled

Media Stream Multicast-direct.................... Disabled

CCX - AironetIe Support.......................... Enabled

CCX - Gratuitous ProbeResponse (GPR)............. Disabled

CCX - Diagnostics Channel Capability............. Disabled

Dot11-Phone Mode (7920).......................... Disabled

Wired Protocol................................... 802.1P (Tag=3)

IPv6 Support..................................... Disabled

Passive Client Feature........................... Disabled

Peer-to-Peer Blocking Action..................... Disabled

Radio Policy..................................... 802.11a only

DTIM period for 802.11a radio.................... 1

DTIM period for 802.11b radio.................... 1

Radius Servers

   Authentication................................ 10.240.85.171 1812

   Authentication................................ 10.240.85.172 1812

   Accounting.................................... 10.240.85.171 1813

   Accounting.................................... 10.240.85.172 1813

   Dynamic Interface............................. Disabled

Local EAP Authentication......................... Disabled

Security

   802.11 Authentication:........................ Open System

   Static WEP Keys............................... Disabled

   802.1X........................................ Disabled

   Wi-Fi Protected Access (WPA/WPA2)............. Enabled

      WPA (SSN IE)............................... Disabled

      WPA2 (RSN IE).............................. Enabled

         TKIP Cipher............................. Disabled

         AES Cipher.............................. Enabled

      Auth Key Management

         802.1x.................................. Enabled

         PSK..................................... Disabled

         CCKM.................................... Enabled

         FT(802.11r)............................. Disabled

         FT-PSK(802.11r)......................... Disabled

FT Reassociation Timeout......................... 20

FT Over-The-Air mode............................. Enabled

FT Over-The-Ds mode.............................. Enabled

CCKM tsf Tolerance............................... 1000

   CKIP ......................................... Disabled

   Web Based Authentication...................... Disabled

   Web-Passthrough............................... Disabled

   Conditional Web Redirect...................... Disabled

   Splash-Page Web Redirect...................... Disabled

   Auto Anchor................................... Disabled

   H-REAP Local Switching........................ Enabled

   H-REAP Local Authentication................... Disabled

   H-REAP Learn IP Address....................... Enabled

   Client MFP.................................... Optional

   Tkip MIC Countermeasure Hold-down Timer....... 60

Call Snooping.................................... Disabled

Roamed Call Re-Anchor Policy..................... Disabled

SIP CAC Fail Send-486-Busy Policy................ Enabled

SIP CAC Fail Send Dis-Association Policy......... Disabled

Band Select...................................... Disabled

Load Balancing................................... Disabled

Any thoughts or suggest would be appreciated.

[Scott Fella]

Try to set the wireless policy to all first. Then after that test I would disable 2.4 on the client and then set the SSID to 802.11a only and see if that works.

Thanks,

Scott Fella

Sent from my iPhone

[chris.brunt]

I have disabled n and 802.11a before on the client with no difference but can't do it on the ssid as we have b/g only devices that connect.

[Scott Fella]

You have this on your ssid:

Radio Policy..................................... 802.11a only

So how is your clients using the 2.4ghz?

[chris.brunt]

Mikes is set to a only my radio policy is set to all see my post further up.