Resolv.conf search parameter limit

Kevin Darcy kcd at
Tue Nov 2 21:58:42 UTC 1999

Last time I checked, there was a limit of 6 search components. I doubt that
this would be particularly platform-specific, since the resolvers shipping
from major Unix vendors generally derive from the same codebase.

My recommendation: use FQDN's for everything. Nowadays it's relatively rare
for users to have to type out a whole hostname anyway, so why waste
DNS resources *guessing* at domain names, which is essentially what
searchlists implement? With 10 searchlist elements, assuming even
distribution of names throughout the domains, you're going to waste an
average of 4.5 queries before you get the real answer. Is it really worth
spending that much more in DNS resources for a mere shortname *preference*?
And what about collisions, i..e. the same shortname in multiple domains?
How do you deal with that? Some here at DaimlerChrysler have already been
down the searchlist path and learned their lesson the hard way. Don't make
the same mistake. Just say no to searchlists.

- Kevin

lisaac29 at wrote:

> Is there a limit to the number of domain names listed in the search
> parameter for the resolv.conf file? I have a network monitoring
> application monitoring different customer environments,  and I wish to
> use the ordinary name instead of the fully qualified domain name (FQDN).
> I have 10 different customer second level domains, and I will add all 10
> too the search parameter. I have not found any documentation which
> identifies a limit to the number of domains listed on the search
> parameter in the resolv.conf file. The network monitoring applications
> reside on Linux, Solaris, and HPUX. I appreciate any input!
> Sent via
> Before you buy.

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