IP Forwarding Virtual Server to all external (internet) IP addresses

I'm looking to create an IP Forwarding Virtual Server, which can forward all traffic from a specific back-end VLAN (id: 819) to all external/internet IP addresses only.

this can be achieved by using source setting in virtual server configuration.

Could someone advise how this could be achieved please and if an iRule is required, in order to match the destination traffic to be only external IP addresses, please?

if you want to drop/reject packet based on destination, you can use IP::addr or class match commands and then drop or reject packet.

iRule to block a specific destination IP?