dns server redundancy

[Mark Andrews]

> Kris wrote:
> 
> >What's the best way to have dns server redundancy?  In my case, we have
> >issues with running out of recursive queries (we've jacked that limit up to
> >10000).  From what I've read, it seems my best bet is to add more
> >nameservers to the mix.  If I set up the zone information for the nameserver
> >as so:
> > 
> >
> >nameserver        600       IN         A          10.0.0.3
> >
> >nameserver        600       IN         A          10.0.0.4
> >
> >nameserver        600       IN         A          10.0.0.5
> >
> > 
> >
> >does this mean that requests for nameserver will be divided equally among
> >the 3 servers listed?  Will this, then, help alleviate the issue we're
> >having with server failure due to excessive recursive lookups?
> >
> No, the address that a name resolves to has nothing logically  to do 
> with what nameserver you ask to resolve it. If you want to spread out 
> the load from a bunch of recursive clients the most straightforward way 
> to do so is by changing the resolver configurations on those clients. 
> This isn't so hard if you're using DHCP; in fact, some DHCP products 
> have a "rotate" option which automatically gives out different 
> permutations of a given resolver list to different DHCP clients, 
> specifically for the purpose of spreading out query load.
> 
> Another option, I suppose, is to put load-balancer(s) of some sort 
> between your nameservers and their clients...
> 
>                                                                          
>                                                          - Kevin

	Or find out what queries you are stalling on and fix the problem.
	
		rndc recursing


--
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org