AirPort Extreme 802.11n 4% Packet Loss

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Level 1

11 points

AirPort Extreme 802.11n 4% Packet Loss

I have three laptops (Macbook, HP, and ThinkPad), an iPhone 4, iPad, and a Wii on my wireless network. I replaced an old Linksys 802.11g access point and router with a new Airport Extreme 802.11n.

Everything has been working fairly good except my ThinkPad. The TP has a ThinkPad 11b/g Wireless LAN Mini PCI Express Adapter III card and can connect to everything from coffee shop wireless to my Cisco WLAN using PEAP/WPA2 at work without skipping a beat.

But here at home, with my new Airport - I'm losing about 4% of the pings I run and it'll drop my connection without warning. Almost like the WPA key is rotating, then just dies.

The MacBook has an 802.11n card and can run extended ping tests without dropping a single one.

The HP has an Intel centrino abg card and runs 0% loss as well.

If I connect my old Linksys back up - I get 0% packet loss on WPA2 again, but to the AirPort - 4%.

It's making my wireless network exceptionally frustrating.

Thinkpad T400, Windows 7, 3 x iPod family

Posted on Mar 8, 2011 8:11 PM

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Answer 1

bspiral Author

Level 1

11 points

Mar 9, 2011 2:27 PM in response to bspiral

Okay, I've had some more time to try things - maybe someone will find my troubleshooting helpful if they're in this same issue.

I've enabled the guest network and activated it with WPA/WPA2 Personal security.

When I connect with my ThinkPad, it pings a solid 0% loss. I thought for a moment that maybe it was the AES encryption causing the issues because my laptop connected to Guest using TKIP.

Couldn't be that lucky. I reset the private network to also use WPA/WPA2 Personal security and rebuilt the wireless connection that my laptop is using the specifically use TKIP. 4% packet loss.

At this point - it could magically be fixed by a firmware update in the future - but I can't wait that long. I've given up trying to get my ThinkPad T400 and AirPort Extreme to play nice.

I pulled my old WRTG-54 Linksys 802.11abg wireless router out of storage and turned off all DHCP features, SSID broadcast, and plugged one of its LAN ports into the AirPort's LAN port.

Now my ThinkPad connects to this hidden wireless network (with 0% loss) while the rest of my gear happily connects to the AirPort without a hiccup or complaint.

If anyone would like to comment, I'll be glad to answer.

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Answer 2

bspiral Author

Level 1

11 points

Mar 9, 2011 2:35 PM in response to bspiral

This is what I get when I'm connected to the main wireless network using 802.11g WPA2 (AES or TKIP).

If you'd like to do this test, simply type this command from a command line (or terminal on an OS X computer)

ping -t 10.0.1.1

And when you're done, type CTRL+C to get the statistics. You can let it run for hours and come back.

ping -t 10.0.1.1
...
Request timed out.
Request timed out.
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255

Ping statistics for 10.0.1.1:
Packets: Sent = 100, Received = 96, Lost = 4 (4% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 2ms, Average = 0ms</div>

Now, if I connect to the guest network or my Linksys WRT-G54, I get this:

Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255
Reply from 10.0.1.1: bytes=32 time<1ms TTL=255

Ping statistics for 10.0.1.1:
Packets: Sent = 100, Received = 100, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 2ms, Average = 0ms</div>

Not a single drop... and I'm still pinging the AirPort's IP address, so I know it's not the device itself dropping pings. It must be something funky with my T400's wireless card and the private network, nothing else makes sense.

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