Something interesting...

I run a small DNS server to host 2 domains.  Most of the queries are small
and come from the servers inside to resolve back to the hosts that are
viewing our websites.  This morning, I noticed a huge amount of queries for
1 of my domains as well as our nameserver itself.  All the queries were from
unique ip's and very frequent.  I picked a handful of the ip's to do some
lookups on and they were all DNS servers from different parts of the world.
Any ideas as to what would spawn a sudden increase in queries from unique
ip's for my domain?  The spike occurred for about 10 mins and was pretty
constant.  Its slowed down a lot now.  No changes have been made to my zones
or anything.  I am just curious as to what would spawn this sudden increase
in DNS traffic from many different hosts.  This has never happened before?
 

Any ideas or thoughts are greatly appreciated.

 

Thanks!