I am on a VPS with root access.
Using WHM I followed the instructions here
I put the last octet in my ip address in the domain field. left the TTL as 14400. Set the record type to PTR In the hostname field I put websitename.com
this resulted in a
.in-addr.arpa not found: 2(SERVFAIL) when doing hosts in the command line
I then put the following in my resolv.conf
search websitename.com nameserver xx.xxx.xxx.xx (with the right ip address instead of the x's) nameserver xx.xxx.xxx.xx which resulted in xx.xxx.xxx.xx.in-addr.arpa domain name pointer websitename.com.
checks on dnsstuff.com still say there is no reverse DNS record, however I think when it updates in 24hrs it will then say it is there.
but I just want to double check that I have done this correctly before I leave it 24hrs.