DNSSEC lookaside validation can provide a chain of trust to signed zones whose parents have not yet deployed DNSSEC. DLV validators usually use a registry maintained by the ISC, dlv.isc.org. The DLV spec uses NSEC records to identify empty spans of the registry zone, so a validator does not need to query the registry for names that fall in these spans. A side-effect of this is that you can use the NSEC records to get a list of all the entries in the registry.
# note the hacky difference in trailing dots # to make starting and ending conditions different n=dlv.isc.org while [ $n != dlv.isc.org. ] do r=$(dig +short nsec $n) n=${r%% *} echo $n done
There are only 2664 entries in the DLV at the moment, so it is tiny compared to the number of properly delegated DNSSEC zones. The most popular TLDs in the DLV are:
495 arpa 436 com 254 de 253 org 237 net 64 eu 61 uk 57 info 50 hu 42 nl 37 fr 36 ro 36 ch 32 cz 30 ru 29 us 24 jp 23 br 22 biz 20 it 20 co 20 at 19 be 18 name 18 au