admin@mercury [~]# host yhostco.co.uk
yhostco.co.uk has address 87.117.204.96
yhostco.co.uk mail is handled by 0 yhostco.co.uk.
admin@mercury [~]# host 87.117.204.96
96.204.117.87.in-addr.arpa domain name pointer rapid.jshosts.com.
admin@mercury [~]#
Hope that helps