# DNS nameserver query order in Mac OS X?



## reidpr (Sep 22, 2010)

I have a home network with 2 Macs (10.4 and 10.6) and one Linux box. There is a caching DNS nameserver on the Linux box. I would like the Macs to use the caching server, and only if that is inaccessible fall through to external DNS.

*Do Macs rotate through all the configured nameservers or try them in order until one works?*

I see that "man resolver" under 10.6 says that "if there are multiple servers, the resolver library queries them in the order listed", i.e., yes, it's round-robin as I want and as the RFC specifies.

However, I vaguely recall reading somewhere that not all Mac software uses this resolver library. But I could be misremembering. Can someone confirm that normal Mac DNS resolution is round-robin?

Much appreciated,

Reid


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## Satcomer (Sep 23, 2010)

On 10.6 at least (and maybe 10.4) open System Preferences->Network pane, Advanced button, DNS tab and put the order of DNS servers you want to use.


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