Flaky WiFi Update 3: DNS Whackiness and a Workaround
However, I began to suspect that Parallels Desktop might be the culprit because of the way it placed its own network drivers for its virtual machines right in OS X's network infrastructure (VMware Fusion does not appear to do this). So, I uninstalled Parallels from my Macbook (it needed to be uninstalled anyway since I moved my virtualization work to an iMac). This seems to have eliminated the packet drops from the Macbook. But, I still had problems resolving to many many web sites. FYI: I notified Parallels of my suspicions and they will take a look at it.
My next step was to wipe out my Macbook and reinstall Leopard from DVD. The weird thing is that while the packet drop was gone, I still had problems resolving web sites (Google, Yahoo, etc.) in my web browser. This was BEFORE updating Leopard to 10.5.2. I took the Macbook and plugged in directly to a router using an Cat-5 Ethernet cable and still had problems getting to sites. This eliminated the guess I had about WEP/WPA2 problems.
Opening up a terminal window I took another look at my network and there seemed to be a problem resolving DNS. But, non-Mac boxes (a Windows PC, Pocket PC, and iPod touch) all worked fine with the existing DNS configuration. Taking a look at my ISP's configuration, I plugged in their DNS servers addresses directly into Leopard's network configuration. This seemed to help a lot but did not fix everything.
The Apple Online/Networking discussion group has a number of threads discussing this issue. A couple of threads (including one titled Slow wireless fix) mentioned DNS related issues too and suggested using the free DNS service from OpenDNS.com. I plugged in OpenDNS' primary (208.67.222.222) and secondary (208.67.220.220) DNS server addresses and web access looked a lot more normal that it had in a long time.
The iMac (with Parallels still installed) has about 3% packet loss. But, using OpenDNS' DNS servers has helped a lot. The system seems usable now. Leopard's network issues are resolved nor explained by these workarounds I've tried. But, I at least have useable Macs again.
You can learn more about OpenDNS' service by reading this ComputerWorld article by Preston Gralla...
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Mac
Comments (1)
Read More Entries by Todd Ogasawara.
I had a very similar issue (packet loss and slow wifi, not DNS) when I upgraded my AirPort drivers the other day. I also have parallels and immediately remembered this post (and the previous).
I also noticed that my wireless was only connecting at 24 or 36 (and alternating between them) instead of 56. I removed the AP name from my connection list, and then re-added it - and since then its back to normal.