Server connection lost when connected via WAP200

[mats_webjorn]

Hi,

I have a small Windows SBS 2011 network where two WAP200 (hw-ver 1.0 sw-ver 2.0.6.0-ETSI) provides WLAN access to the network for my Win7 clients. If I connect one of the Win7 clients via one the the WAP200, open a pdf-file and leave it for one hour, and then try to scroll the document, then Acrobat reports an IO-error after 20 seconds. This does not occur if I connect directly to the LAN or via a 3Com AP instead. Similar problems occur if I open Outlook or IE.

It seems like a SMB2 session is created when I open the pdf-file, and that this session is lost for some reason. Is there some PM that kicks in and makes the client inaccessible from the server so that it considers the client gone ?

Regards

MatsW

[jeffrrod]

Dear Mats,

Thank you for reaching Small Business Support Community.

Chances are this is happening due to the Key Renewal Timeout which instructs the Access Point how often it should change the encryption keys. The default is 3600 seconds so I suggest you to increase it from the Wireless/Wireless Security tab and test it.

Please give that a try and let me know if there is any further assistance I may help you with.  I'll be looking forward to hear from you.

Kind regards,

Jeffrey Rodriguez S. .:|:.:|:.
Cisco Customer Support Engineer

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[mats_webjorn]

Hi Jeffrey,

Interesting! Key Renewal definitely has something to do with why the SMB2 session fails after one hour (3600s as the default timeout is for Key Renewal Timeout). I changed it to 10800 and now the issue doesn't occur after one hour.

Can you explain what happens between the WAP200 and the client when the timeout occurs ?

Shouldn't this be transparent to connections between the client machine and server ?

Client is a Win7 machine. Is there something I need to configure on the client to handle this correctly ?

Kind regards

Mats

[mats_webjorn]

Hi Jeffrey,

Sorry, wrong conclusion! It is correct that if I change to Key Renewal Timeout to 10800 and wait for one hour then the problem doesn't occur. But if I change it back to 3600 and wait for 1 hour and 10 minutes then the problem also doesn't occur.

The common factor is that WAP200 is restarted. So something does/doesn't happen some time after WAP200 is reset.

Any idea?

Kind regards

Mats

[mats_webjorn]

Hi Jeffrey,

There's definitely something fishy with the WAP200. I can see the following: If I take a network trace on both my server and the client attached via WAP200 then I can see that suddenly ARP Requests from server doesn't reach the client. This lasts for about 5 minutes when traffic starts to pass thru.

So then I started "ping client -n 10000000' on the server to make sure I had a continous flow of traffic between client and server. Now the problem doesn't occur. But what is odd is that I can see that another client which is attached to the same WAP200 suddenly stops responding to ARP Requests, just as the first client when it didn't have ping running.

This may explain why the SMB2 session fails because if client doesn't respond to ARP Requests (because WAP200 drops connection for 5 minutes) then eventually the file handle is closed.

Do you have some suggestion on how to debug this ?

Kind regards

Mats