View Full Version : Why Doesn't Backup DNS Resolving Work on OSX?

10-26-2004, 11:14 AM
I have two internal DNS. Client machines have both listed in the DNS entry of Network preferences (DNS 1 on the first line and DNS 2 on the second). DNS 1 went down, and DNS 2 did not pick up the querying. When DNS 1 was removed from the list and put DNS 2 at the top of the list, DNS 2 resolved names correctly.

Shouldn't DNS 2 have picked up querying if DNS 1 failed? That is the whole purpose of have serveral DNS entries, is it not?

All machines are Panther 10.3.5.

10-26-2004, 11:40 AM
How long did you wait for DNS 1 to time out?

10-26-2004, 12:31 PM
I don't know. Shouldn't OS X worry about how long to timeout DNS 1 before trying DNS 2?

10-26-2004, 12:48 PM
It should, and does, but you have to wait at least that long to see if DNS 2 is working, which is why I asked: maybe DNS 2 is working fine, but you're not waiting long enough?

10-26-2004, 01:29 PM
It's not only the system that determines the timeout. The application that is asking for DNS resolving can specify a timeout as well. I think Safari specifies a rather short timeout.

You can specify a timeout for testing if you use the utility 'dnstracer' which is available via Fink.