Finding Needed A Records with fping

The last several weeks, I’ve found myself doing a slew of things that have been incredibly dependent on DNS (e.g. Nagios host checks on hosts that would soon change IP addresses).

I found fping in these situations to be the “magic bullet” to help me start narrowing down DNS problems.

e.g. something like: fping -d -g 10.0.0.0/24

-g would let me feed in a weird subnet (or range of IPs), and -d would turn around and ping the host name that the ICMP reply gave me, ultimately giving me the A record someone needed to BIND to help with the transition.

From there, I could use the standard unix tools (grep, sed, etc) to sort whatever output fping crapped out.

Anyone have a “better” way of doing this?