DNS magic?

Web Performance Discuss Test Results
1

Consider the following test:
http://www.webpagetest.org/result/130702_SC_Q8S/2/details/

DNS Lookup in requests #11 and #12 are executed too early? Is it even possible?

2

There’s a couple of things going on there

hints to the browser that it can try to resolve the dns early i.e. before it discovers a resource using that host.

IE10 in general tries to resolve DNS and open connections early but I’m not sure how it’s resolving the second domain so early as the JS that references the images on hd. hasn’t executed before the domain is resolved.

IE10 does lots of DNS caching so perhaps the test agents isn’t clear thing cache properly

3

Looks like IE10 changed things again and the preconnect cache isn’t getting cleared. I’ll look into it. Had the same problem when it first rolled out and had it under control: Performance Matters: Clearing IE's Caches - Not as simple as it appears but it’s possible that I need to kill a different set of processes on Windows 7.

4

[quote=“pmeenan, post:3, topic:8215”]
Looks like IE10 changed things again…[/quote]

Thanks for the explanation.

Btw, awesome article: Performance Matters: Clearing IE's Caches - Not as simple as it appears