in-addr

We can futz around the edges with things like using in-addr.arpa for reverse DNS lookups (but what the hell is using a.arpa address if not hipster techie branding, anyway?), but the majority of the DNS hierarchy?

Authoritative answers can be found from: 103.111.64.in-addr.arpa nameserver = ns3.dreamhost.com.

I seem to remember the massive DDoS Microsoft enacted against the blackhole servers of the RFC1918 in-addr.arpa zones for example, that was borderline criminal.

When an isp gets a ip allocation, they specify the nameservers to use, and are responsible for that "subdomain" of the in-addr.arpa domain.

There is a companion to dig called "host" that is a simple lookup, including looking up in-addr.arpa entries ("host 8.8.8.8").

Of special note, Nmap 5.00 is now able to map IP addresses to AS numbers: "The script works by sending DNS TXT queries to a DNS server which in turn queries a third-party service provided by Team Cymru (team-cymru.org) using an in-addr.arpa style zone set up especially for use by Nmap.

When an isp gets a ip allocation, they specify the nameservers to use, and are responsible for that "subdomain" of the in-addr.arpa domain.

There is a companion to dig called "host" that is a simple lookup, including looking up in-addr.arpa entries ("host 8.8.8.8").

Of special note, Nmap 5.00 is now able to map IP addresses to AS numbers: "The script works by sending DNS TXT queries to a DNS server which in turn queries a third-party service provided by Team Cymru (team-cymru.org) using an in-addr.arpa style zone set up especially for use by Nmap.