Saturday, June 27, 2009

Slow Mac DNS lookup fixed

Okay, it turns out Comcast was at fault after all. While the signal to the cable modem was good, apparently Comcast DNS servers no longer play nice with OS X Leopard, resulting in my hideous lookup delays. After turning off IPv6 (no effect) and manually configuring my Ethernet connection to use Open DNS Servers 208.67.220.220 and 208.67.222.222 (that was the ticket!) in System Preferences->Network, everything was back to normal, sites like nba.com, Google, mlb.com et. al were all working fine. It looks like when Apple went up to Leopard they changed the nature of their DNS queries to match the new standard, while Comcast's backwards DNS servers are still in old school mode. Thank you Open DNS servers and all the people on the internet who suggested to change to them.

3 comments:

Brian said...

Thank you! Thank you! Thank you! I have been having problems with this for weeks. It used to be fine, but for some reason DNS lookups got really slow this summer. I added the two DNS servers you listed and it is instantly better.

Anonymous said...

Thanks!! Worked for Telenor, Norway as well :-) Seems they have the same problem...

mludd said...

There is no "new DNS standard" it's just that mDNSResponder in Snow Leopard is broken in several ways, maybe one of these days they'll actually get around to fixing it (read: return to the 10.5 code)