[dns-operations] The possible problems after May 5th

[Matthew Dempsky]

On Thu, Apr 8, 2010 at 6:35 AM, bert hubert <bert.hubert at netherlabs.nl> wrote:
> Try it. Block UDP for your resolver and see how far you get.

For fun, I patched dnscache to only send queries over TCP and then
tried resolving a bunch of popular domain names with it.  I tested the
first 60 entries in Alexa's top domains and was unable to resolve the
following names:

www.live.com
www.baidu.com
www.msn.com
www.qq.com
www.taobao.com
www.myspace.com
www.microsoft.com
www.bing.com
www.ebay.com
www.fc2.com
www.soso.com
www.conduit.com
www.aol.com
www.bbc.co.uk
www.apple.com
www.youku.com
www.ask.com

I also tried a bunch of other names that randomly came to mind, and
found these didn't resolve either:

www.nytimes.com
www.latimes.com
www.bing.com
www.cnn.com
www.msnbc.com
www.foxnews.com
www.fox.com
www.myspace.com
www.redhat.com
www.akamai.com
www.alterslash.org
www.reddit.com
www.usnews.com
www.upenn.edu
www.rice.edu
www.oracle.com
www.qualcomm.com
www.alcatel-lucent.com

So whatever the state of DNS over TCP support in software may be, the
DNS servers for a large number of popular websites at least don't
currently have it enabled.