Archived from groups: microsoft.public.windows.networking.wireless (
More info?)
Also, since this seems to work "sometimes" for you, if you have a different
wireless card, you can disable the internal one and see if the new just one
roams better.
Always use the "latest" drivers from your NIC manufacturer. Some older ones
can be buggy. : )
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"Carl DaVault [MSFT]" <carlda@online.microsoft.com> wrote in message
news:uZZjuZQzEHA.3408@tk2msftngp13.phx.gbl...
> Assuming everything is set up correctly with the AP's (they all have the
> same SSID, the same security configuration, and user the same DHCP
> server), it's still possible that you're losing your wireless connection.
> This would be a function of the wireless driver, not XP. Ideally the
> driver will switch between access points seamlessly (without
> disconnecting). XP only plumbs down the SSID and the security settings.
>
> That said, you can try an experiment to check your connectivity: walk
> around running "ping <ipaddress_of_database_server> -t -w 1". There may be
> some "dead" spaces in your network coverage that would cause the driver to
> disassociate from the AP. You can optionally experiment with ping's length
> value (see ping -? for help) to see if the problem only happens with
> larger packet sizes.
>
> You also might want to do an "ipconfig /all" after you lose a connection -
> to make sure you have the same IP (all AP's should be served by the same
> DHCP server so you get the same IP address).
>
> If you actually ARE losing connectivity (meaning that the network
> disconnects), then you won't be able to send or receive packets, the media
> state of your adapter may change, etc. Ideally your application would be
> robust enough to accomodate brief network outages, but if this is not the
> case, you can try using a static IP address (and excluding that address
> from the DHCP lease pool).
>
> If you do know for sure that you are losing connectivity, make sure your
> network is at the top of the list in the wireless settings and the SSID is
> NOT hidden on the AP's. Some wireless drivers have a tough time with
> hidden SSID's and Windows only looks for them when all visible networks
> have been ruled out as possible connections.
>
> If you try to use a static address, as a last resort you might also want
> to try changing the DisableDHCPMediaSense registry value. I haven't
> personally tried this, but it might help your laptop think the connection
> is still active (even when it is not). Only try this with a static address
> (not DHCP). See
http://support.microsoft.com/?kbid=239924 . You may need
> to reboot for it to take effect.
>
> You are likely using a TCP connection for your database access. If you
> want, you can try sniffing with netmon to see whether (and why) the
> database connection is closing. (Does it happen on the client side or
> server side?) Does the routing infrastructure you have in place take time
> to start shifting packets from one subnet to another? If each AP is on a
> different subnet then you're probably using different DHCP servers anyway
> and the TCP connection dropping would be a side-effect of an IP-address
> change.
>
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>
> "Dave Ploch" <dave_ploch@2wheeltech.com> wrote in message
> news:10p78qgor2gs4a4@corp.supernews.com...
>> We have recently expanded our site and now need to add 2 more access
>> points. The first was an Aironet 1100 (Cisco). We have purchased two
>> more of these.
>>
>> With all three ap's set to the same SSID / different channels I have a
>> tablet (Toshiba running Tablet XP w/ Intel 2200b/g wireless) and roam
>> around the area doing production management functions using an app
>> (purchased) connecting to an MSSQL db in the office. Everything seems to
>> work fine, it roams to each of the AP's but every once in a while it
>> causes the app to lose communications with the db. It appears that this
>> happens if the system decides to roam while a query is being processed.
>>
>> At this point the only authentication being done is MAC address filtering
>> and no encryption. (starting out as easy as possible since the security
>> issues are fairly limited in this installation).
>>
>> I read the thread going on about WDS and have read the tech notes on the
>> Cisco site but this looks quite complex and I don't want to start down
>> the wrong path since it looks like a significant learning curve.
>>
>> Any ideas on what we can do to resolve this issue?
>>
>> DaveP
>
>