Virtual Server IP Address in SERVER_DATA event

You don't need a global variable to pass the virtual server IP address from the CLIENT_DATA event to the SERVER_DATA event. A local variable will work just fine. For example:

when CLIENT_DATA { set vipAddress [IP::local_addr] }

when SERVER_DATA { log local0. "Client is connected to $vipAddress" }

In other words, set variable vipAddress on the CLIENT_DATA event, and refer to the variable as $vipAddress on the SERVER_DATA event.