11.251.57.103.in-addr.arpa.
Question and response
Question
dig 11.251.57.103.in-addr.arpa. PTR
Answer
11.251.57.103.in-addr.arpa. 600 PTR 11.251.57.103.in-addr.arpa.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0