[dns-operations] A record round-robin behavior

Mark K. Pettit pettit at yahoo-inc.com
Wed Apr 19 09:31:11 UTC 2006

I'm trying to figure out how BIND's A record round-robin behavior works.

My understanding has always been that if you have an A record rotation 
something like this:

foo	A
foo	A
foo	A

that the very first query for "foo" to your server would return the 
records in the order ".4, .5, .6".  Then the very next query for "foo" 
would return the records in the order ".5, .6, .4".  Then ".6, .4, .5". 
  Then it would start over again.

Thus if you ran the query three times, you'd get three different initial 
A records back.

The behavior I actually observe seems completely random.  I do get 
records in the order I expect (e.g. no ".6, .5, .4"), but it appears to 
be random which will be listed first.


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