dns_check advice needed regarding cached results

[optbin]

Hi,

I have been using Nagios for a while and it seems to be working fine.

However, I just ran into an issue with check_dns passing a DNS server due to a cached result. It seems to me that if DNS_check is always checking the same resolvable host, the DNS server will return a result from its cache (until expiry). So although this server couldn't resolve anything else due to a failure with its forwarders, Nagios reports all is OK.

My interest in the checking DNS is for basic server functionality and not about any particulars on a specific host.

I have been looking into the +norecurse feature of dig, but find that some DNS refuse queries with this option.

I welcome suggestions as to how to best determine if a DNS server is really working or not.

Thanks in advance.

Mike

[tmcdonald]

I'm not incredibly familiar with DNS configuration, but if it is serving up cached info I'm not certain of a way to force it to do otherwise. Try this, perhaps?

http://serverfault.com/questions/372066 ... sing-cache