Using FQDNs in Aliases¶
Fully Qualified Domain Names (FQDNs) may be used in network aliases, with some caveats.
On pfSense 2.0 and later, the hostnames are checked and updated every 5 minutes.
On pfSense 2.1 and later, this interval may be manually set under System > Advanced on the Firewall/NAT tab.
DNS names that use very low TTLs and change frequently, such as round robin entries, are not reasonable to use in this fashion. This means that large sites like google.com, which return a different set of IP addresses with each query, would not be a viable in an alias.