We have seen DNS translate a name to an IP address, DNS can also do IP address to name translations.
Now sometimes you might need this - if I gave you an address of 196.7.138.125 you might want to know what name this is.
So we have a means where DNS converts from an IP address back to a name and we can use our dig command again - "dig -x 196.7.138.125" It does a reverse translation - and 196.7.138.125 should give us a name in return.
debian:/ # dig -x 196.35.20.131 ; <<>> DiG 9.2.3 <<>> -x 196.35.20.131 ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 27898 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;131.20.35.196.in-addr.arpa. IN PTR ;; AUTHORITY SECTION: 35.196.in-addr.arpa. 10463 IN SOA ns1.is.co.za. \ dns-admin.is.co.za. 2004072000 28800 7200 604800 86400 ;; Query time: 4 msec ;; SERVER: 192.168.2.7#53(192.168.2.7) ;; WHEN: Tue Jul 20 11:41:24 2004 ;; MSG SIZE rcvd: 102 debian:/ # |