round robin

phn at phn at
Sun Feb 17 12:02:51 UTC 2002

WebReactor Networks <bind at> wrote:
> More to the point, BIND does not do any round-robining.  Period.  BIND simply returns both of the A records.  The client application chooses which of those A records to use.  In your case the "client application" is the Windows resolver.

Close.  BIND by default returns all A records, the order between them is 
randomized. This is controllable with the "rrset-order" statement in bind-9.

Next, what has been observed is that the ping command will do 
one name lookup and then use the first address for all "pings".

Repeating the ping will most likley show a random selection ( unless 
some vendor has created a "nameserver-cache". This cache should in
almost all cases be turned off and disabled)

> See < > for more info.

> -------- Original Message --------
> Subject: RE: round robin
> Date: Fri, 15 Feb 2002 11:04:04 -0500
> From: "Haygood, David" <david.haygood at>
> To: "'bind-users at'" <bind-users at>

> If your Windows Desktop is 2K or XP its cache is 24 hours.

> -----Original Message-----
> From: Brian Noecker [mailto:bnoecker at]
> Sent: Wednesday, February 13, 2002 6:26 PM
> To: 'bind-users at'
> Subject: round robin

> Is there a trick for round robin to work correctly?  I've got the following
> scenario:

> Two Bind 9.2.0 jailed servers, one master, one slave with either of the
> following A record options:

> test    10    A
> test    10     A

> or 

> $TTL 2h

> test     10    A
>      10    A

> Now, on the both servers, they use themselves as primary DNS in resolv.conf.
> The master is on a solaris box, the slave a RH7.2 box.

> When I'm on the master itself and ping test, is the only answer I
> get back.  When I'm on a windows desktop using the master as its DNS server,
> I only get  When I'm on the slave server and ping, I get about a
> 30/70 split on my returns.  

> Should I expect consistency on the round robin nature of Bind?  

Yes. You need to ask bind several times however.

> Thanks in advance.

Peter Håkanson         
        IPSec  Sverige      (At the Riverside of Gothenburg, home of Volvo)
           Sorry about my e-mail address, but i'm trying to keep spam out.
	   Remove "icke-reklam" and it works.

More information about the bind-users mailing list