Last year I tried to attack the task of cleaning up the DNS. Brian at one
point did an AND against the gateway subnets with the DNS and it produced
~19k A records - hundreds of times what is valid or even being used.
So as a curiosity exercise, I wrote some script to import the DNS into
MySQL. The result was 16653 unique callsigns in the DNS and 2211
aliased/bad call signs as of June 2015.
I then imported the FCC amateur database and compared it to US (A,K,N,W)
callsigns - that produced 3742 unique US callsigns matching the DNS. Out
of those, 1373 callsigns matched an expired, canceled or terminated
license. This doesn't take into account all the vanity call signs for the
1x2/2x2/2x1/1x3 callsigns which may be attributed to another operator.
While we can get good grips on the US callsigns, as soon as it crosses an
international border, it goes to pot as every country has their own
licensing structure. Many do not have online databases. So that's what
we're faced with.
Ideas welcome as to how we can validate the DNS tables.