Maintained by: NLnet Labs

[Unbound-users] Unbound x Bind - Round robin DNS

Paul Wouters
Fri Dec 14 03:22:48 CET 2012


On Fri, 14 Dec 2012, Leandro Anjos Moura wrote:

> My server has an authoritative Bind round robin configuration for a
> given record (rrset), where the ips are of different networks, eg:
>
> mail.emp.intranet. A 192.168.50.20
>                                   A 192.168.50.21
>                                   A 10.16.16.20
>                                   A 10.16.16.20
>
> When my application directly query my server Bind all ips are utilized
> in connection, but when my application query my server Unbound ips
> network 10.XXX are never recovered.
>
> My configuration is:
>  - Centos 5.4: Application Server
>  - Centos 6 / Bind 9.9.1: authoritative server
>  - Centos 6 / Unbound: cache / recursive

I believe bind randomizes the order, while unbound just returns the
static order. the application is apparently always picking the first
entry.

More people have been hit by this in the past. Perhaps a switch
could be added to unbound to randomize these like bind does.
(even though round robin DNS as load balancer isn't a terribly
  good idea to begin with)

Paul