Setting up a host object doesn't work if a hostname can map to multiple IP addresses because of a load balancer, etc. I use a workaround where if a hostname can resolve to a limited number of known IP addresses, first make a network object for each IP, with a slightly different name. Assume
www.foo.com can resolve to 2 different IP addresses . Make host objects:
foo.com_dest1 11.12.13.14
foo.com_dest2 15.16.17.18
then make a group object
foo_group
that contains the host objects
foo.com_dest1
foo.com_dest2
and set the group object up in the NAT. This workaround does have limitations, it works best when only a small number of known static name resolutions is used. If it is a large number, or very dynamic, or any are unknown, it will be difficult and not work well.
