IPconfig /flushdns

  • Thread starter Thread starter Chris Hadlock
  • Start date Start date
C

Chris Hadlock

when the /flushdns command is used on a W2K worstation,
the Services.exe uses up 100% of the CPU, and hangs the
workstation for a indefinite period of time. Sometimes,
but not always requiring a reboot. The same command on
the Domain Controllers works as expected.

Has anyone experienced this?

Thanks
Chris
 
when the /flushdns command is used on a W2K worstation,
the Services.exe uses up 100% of the CPU, and hangs the
workstation for a indefinite period of time. Sometimes,
but not always requiring a reboot. The same command on
the Domain Controllers works as expected.
Click to expand...

Large Hosts file most likely. If you run the "DNS Client" then
it maintains a DNS cache comprising the host file contents and
any resolved DNS name.

On flushing it rebuilds the host file portion -- I had a 75,000
entry test hosts file that took about 1 hours at 100% to rebuild
on each re-start, flush, or even edit of the file.
 
HM> I had a 75,000 entry test hosts file that took about 1 hours
HM> at 100% to rebuild on each re-start, flush, or even edit of
HM> the file.

My goodness!
 
Jonathan de Boyne Pollard said:
HM> I had a 75,000 entry test hosts file that took about 1 hours
HM> at 100% to rebuild on each re-start, flush, or even edit of
HM> the file.

My goodness!
Click to expand...

I was experimenting with Host based denial of porn/spam/bad
sites.

Just curious really but I ended up pre-loading the cache of a BIND
server due to the performance problem (and multiple machine distribution
and management issues) with Hosts files of large size.

Unfortunately, MS DNS cannot preload the cache with anything but
root DNS servers.
 
Back
Top