Windows XP DNS Cache

Windows caches DNS responses to speed up network access, but sometimes this can cause a problem.  Positive responses (i.e. successful lookups) are cached for 24 hours, and negative responses (i.e. failed lookups) for 5 minutes.

If you make changes to DNS and want to test the results straight away, you need to clear the cache with:

ipconfig /flushdns

You can view the current cache with:

ipconfig /displaydns

or

ipconfig /displaydns | more

to see a screen at a time