If you can see this check that
When trying to find the hostname of ip 10.5.6.7, which of the following
is a step in the process.
|A.||There is a initial DNS lookup of domain 6.5.10.IN-ADDR.ARPA
|B.||There is a initial DNS lookup of domain IN-ADDR.ARPA.6.5.10
|C.||There is a initial DNS lookup of domain 10.5.6.IN-ADDR.ARPA
|D.||There is a initial DNS lookup of domain IN-ADDR.ARPA.10.5.6.7
|E.||There is a initial DNS lookup of domain IN-ADDR.ARPA.10.5.6
The IP is reversed with the host part of the address removed. The ARPA domain is then added to the end.
The ARPA domain appears last in the name, not first.
The IP part of the lookup is reversed before it is applied to the ARPA domain.
ARPA domain appears last, the IP is reversed and appears first, minus the host number.
Only the IP is reversed. The ARPA domain must appear last.