03-12-2011, 01:34 AM

Dear All,

I have a problem with my Internet connection. Since two or three weeks I have a strange problem. After restoring my MacBook from TimeMachine, my Internet seemed to be too slow. I did ping and it lookd fine! so I installed a Windows XP virtualmachine (VirtualBox Guest). In bridge mode the internet speed is pretty good, but on the host machine its slow! I couldn't find any solution so I did a complete reinstallation from Mac OS X DVD, but still the same problem presists! Now I am posting this from Windows XP. Have any of you encountered such a problem or know the solution?

Thanks,

03-12-2011, 02:06 AM

You might want to try changing two settings to see if they make a difference in your Web browsing speed. (Actually, both of these often make a significant positive difference for just about everyone.)

1) Try turning off IPv6.

If you are running OS X 10.4 (Tiger):
Quit all browsers.
Go into System Preferences --> Network --> go to the "Show:" dropdown
menu and have it show Built-in Ethernet -->
TCP/IP tab --> Configure IPv6 button -->
change the setting from Automatic to Off.

If you are running a later version of OS X:
Quit all browsers.
System Preferences -> Network -> choose the Ethernet tab in the far
left column --> Advanced button -> TCP/IP tab --> Configure IPv6:
dropdown menu, choose Off --> Okay button.

The reason that turning IPv6 off may improve performance is that some DNS servers do not properly respond to IPv6 requests. As a result, your computer has to time out waiting for a response and then try a secondary DNS server.

In recent versions of OS X, IPv6 typically is on (set to "automatic") by default, but not used. You have nothing to lose by turning IPv6 to "off" and then seeing if performance improves. When I first turned it off, I tested it out by going to a Web site that I visit often that is typically slower to load than any other Web site that I have visited. It came up instantaneously, as if it had been cached! I had never seen it do that previously.

Changing your IPv6 setting isn't immutable. If you don't realize a performance improvement, just change it back to "automatic." I can't think of any downside to trying this out.

2) Find the fastest domain name server (DNS).

Quit all browsers.
Go into:
System Preferences --> Network --> Built-in Ethernet
and write down the numbers for the domain name server(s) (DNS) to save them.

You can find the domain name server(s) that provide the best performance for your Mac using:

NameBench (free)
namebench - Project Hosting on Google Code

NameBench will take about 5 minutes to run. Be patient. Use the fastest DNS it finds to replace the existing setting in Network in System Preferences.

Now launch your browser and visit several Web sites. You can expect a significant Web browsing performance increase after using the fastest domain name server suggested by NameBench!

Note: Every time you run NameBench, it is likely to give you a different result. This is normal. Don't become manic about running NameBench. Run it during the time of day that you do most of your Web surfing. Use that result. If your Web browsing subsequently appears to have slowed down noticeably at any point, you can run it again.

Please let us know if these tips help.

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Randy B. Singer
Co-author of The Macintosh Bible (4th, 5th, and 6th editions)

Macintosh OS X Routine Maintenance
OS X Maintenance And Troubleshooting
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