Firefox slow with Visual Studio 2008

Posted by Stephan Kristyn on March 26th, 2010 / No Comments

If you install Visual Studio 2008 you may notice that Firefox is starting to get inredibly slow.

After doing some research I found out that this problem is owed to the fact that we are living in a world that is transitioning from IPv4 to IPv6.

The Mozilla Wiki states:

“IPv6 was designed in part to solve the problem IPv4 will soon be facing: the exhaustion of all possible IP addresses. Mozilla implemented IPv6 support in early 2000, but that support did not receive widespread testing until recently as IPv6-capable OSs and network software/equipment became more common.

One particular bug that has appeared exists not in Mozilla, but in IPv6-capable DNS servers: an IPv4 address may be returned when an IPv6 address is requested. It is possible for Mozilla to recover from this misinformation, but a significant delay is introduced.”

The workaround Mozilla suggests is to turn off IPv6 in the Firefox about:config page by altering the boolean value of network.dns.disableIPv6 to true. This would disable all IPv6 in Firefox, so a better workaround would be to set network.dns.ipv4OnlyDomains to localhost. I tested both methods with FF 3.5 and they work instantly. I recommend the latter method.

This problem was first reported by the blog scottonwriting.net.