I have a custom DNS server and I noticed that the logs are getting filled with queries of type
ANY for the
. (single dot) domain, instead of
www.example.com. or other domains which it could handle. It is not recursive and only handles very specific subdomains of the main domains, which are managed by commercial DNS hosting providers.
I don't respond at all to any query for domains which are not mine, because I want to avoid to be misused for DNS Amplification attacks. Please correct me if this is bad. Prior to this I was responding with
5) response codes.
So I'm not really sure if these are some kind of attacks or a normal thing which happens. These are bursts of about 5-10 seconds in length with about 5-10 queries per second which happen a couple of times a minute.
Since I was storing these queries in a database I see that the IPs creating the most queries are very specific IPs from AT&T, then Comcast, although they could be spoofed.
What do I do with this? Ignore it because there is nothing I can do about it? It doesn't create any noticeable load on the server.