Ghost Console Clients will not be able to connect to the Ghost Console if the PIX firewall is blocking access to the multicast group ID address of 229.55.150.208.
Configuring the PIX firewall to allow the clients to multicast to the multicast group address 229.55.150.208, and configuring the firewall to allow the Ghost Console to send unicast UDP traffic to the clients will resolve this.
Alternatively, using the Ghostcast method with either the switch -JADDR=<serveripaddress>, or by entering the server's IP address after entering the session name will work. This bypasses the need for a multicast communication for client identification.