[Pdns-users] About the mechanism of forward-zones when using multiple ips for one zonename.

[Peter van Dijk]

Hello,

On 23 Feb 2015, at 6:09 , Hongyi Zhao <hongyi.zhao at gmail.com> wrote:

> forward-zones Comma separated list of ’zonename=IP’ pairs. Queries for zones listed here will be forwarded to the IP address listed. Since version 3.1.5, multiple IP addresses can be specified. Additionally, port numbers other than 53 can be configured.
> Sample syntax: forward-zones=example.org=203.0.113.210:5300;127.0.0.1, powerdns.com=127.0.0.1;198.51.100.10:530
> 
> I just want to know the mechanism when we use multiple ip for Query a zone.  I mean is this process sequel or  parallel?  When we using multiple ip for resoving a specific domain-name, which answer given by the forwarders should be picked up by PowerDNS Recursor and then return it to user's client program?

It’s best to assume the process is random. For any given query, the resulting data can come from any of the IPs, and there is no guarantee from which one. So, in general, make sure your backend IPs agree on the data!

Kind regards,
-- 
Peter van Dijk
Netherlabs Computer Consulting BV - http://www.netherlabs.nl/