On Sun, 2008-03-09 at 22:02 -0700, John R Pierce wrote:
Manish Kathuria wrote:
What is the maximum number of nameservers mentioned in /etc/resolv.conf which will be queried while looking up a hostname or IP address in the present version ? Earlier implementations had a ceiling of 3 name servers which could be queried. Has there been any increase ?
only one server is ever queried. only if it if it can't be reached at all will it fall back on the 2nd one (and if that can't be reached, the 3rd) a answer of 'host not found' from the primary server does /not/ trigger any fallback, instead it returns "not found".
so, why would you need more than 3 ? DNS servers should have a .9999 uptime.
The idea is to switch between multiple internet links for the same internal network, without making frequent changes to /etc/resolv.conf. The ISPs here don't allow DNS look ups from an IP not belong to their address, so a number of look up requests get denied when the outgoing connection is through another ISP. Of course, I can run a caching nameserver on the small network or use Open DNS servers but that adds to the delay.
Thank you,
Manish