So in the process of conducting some network discovery for a new client I have discovered the following ...

C:\>ping -a x.x.x.10

Pinging 10.domain.tld [x.x.x.10] with 32 bytes of data:

Reply from x.x.x.10: bytes=32 time=83ms TTL=111
Reply from x.x.x.10: bytes=32 time=108ms TTL=111
Reply from x.x.x.10: bytes=32 time=107ms TTL=111
Reply from x.x.x.10: bytes=32 time=107ms TTL=111

Their DNS is hosted by their ISP and something is obviously wrong as their reverse dns is appearing as domain.tld. Could anyone shed some light on exact what is wrong so that I can notify their ISP?