round-robin on bind9.2.1

[Gregory Hicks]

> Subject: RE: round-robin on bind9.2.1
> Date: Sun, 20 Feb 2005 11:20:37 -0800
> From: "Boyack, Kurt" <Kurt.Boyack at pyxis.com>
> To: "Steven Job" <list3 at wwwcrazy.com>, <bind-users at isc.org>
[...snip...]
> 
> So rrset-order was re-implemnted in a later version of 9.x, but isn't 
> round-robin still the default? The original question was how to do
> round-robin, not how to turn it off.

How to implement?

[...snip part of zone file...]
machine.name	IN A 1.2.3.4
		IN A 1.2.3.5
		IN A 1.2.3.6
[...snip rest of zone file...]

For each query made to this nameserver, BIND will cyclicly return all IP 
addresses but the FIRST one returned rotates.

Ie:  First is returned 1.2.3.4, 1.2.3.5, 1.2.3.6...
at the next query is returned 1.2.3.5, 1.2.3.6, 1.2.3.4
At the next query if returned 1.2.3.6, 1.2.3.4, 1.2.3.5
...

And so it goes.  Depending on how busy your server is, you may see the
first IP, the second IP, the third IP, the first IP, ...  But the FIRST
IP returned is going to vary.  If you query fast enough, you will see
the rotation.

Try www.hp.com to see how it works.

ghicks-vpn% nslookup www.hp.com
Server:  cds238.Cadence.COM
Address:  158.140.128.1

Non-authoritative answer:
Name:    www.hpgtm.speedera.net
Addresses:  161.114.22.111, 161.114.22.105
Aliases:  www.hp.com

ghicks-vpn% !!
nslookup www.hp.com
Server:  cds238.Cadence.COM
Address:  158.140.128.1

Non-authoritative answer:
Name:    www.hpgtm.speedera.net
Addresses:  161.114.22.111, 161.114.22.105
Aliases:  www.hp.com

ghicks-vpn% !!
nslookup www.hp.com
Server:  cds238.Cadence.COM
Address:  158.140.128.1

Non-authoritative answer:
Name:    www.hpgtm.speedera.net
Addresses:  161.114.22.105, 161.114.22.111
Aliases:  www.hp.com

ghicks-vpn% !!
nslookup www.hp.com
Server:  cds238.Cadence.COM
Address:  158.140.128.1

Non-authoritative answer:
Name:    www.hpgtm.speedera.net
Addresses:  161.114.22.111, 161.114.22.105
Aliases:  www.hp.com

ghicks-vpn% !!
nslookup www.hp.com
Server:  cds238.Cadence.COM
Address:  158.140.128.1

Non-authoritative answer:
Name:    www.hpgtm.speedera.net
Addresses:  161.114.22.111, 161.114.22.105
Aliases:  www.hp.com

ghicks-vpn% !!
nslookup www.hp.com
Server:  cds238.Cadence.COM
Address:  158.140.128.1

Non-authoritative answer:
Name:    www.hpgtm.speedera.net
Addresses:  161.114.22.105, 161.114.22.111
Aliases:  www.hp.com

ghicks-vpn% !!
nslookup www.hp.com
Server:  cds238.Cadence.COM
Address:  158.140.128.1

Non-authoritative answer:
Name:    www.hpgtm.speedera.net
Addresses:  161.114.22.111, 161.114.22.105
Aliases:  www.hp.com

ghicks-vpn% 

Hope this helps!

Regards,
Gregory Hicks



> 
> 

---------------------------------------------------------------------
Gregory Hicks                           | Principal Systems Engineer
Cadence Design Systems                  | Direct:   408.576.3609
555 River Oaks Pkwy M/S 6B1             | Fax:      408.894.3479
San Jose, CA 95134                      | Internet: ghicks at cadence.com

I am perfectly capable of learning from my mistakes.  I will surely
learn a great deal today.

"A democracy is a sheep and two wolves deciding on what to have for
lunch.  Freedom is a well armed sheep contesting the results of the
decision." - Benjamin Franklin

"The best we can hope for concerning the people at large is that they
be properly armed." --Alexander Hamilton