I have two buildings in two diferent locations each one with a Cisco ASA5520 to provide VPN access. I want to configure load-balancing between them but I can´t have both outside interfaces in the same subnet. Reading the document: http://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a00805fda25.shtml, it is stated that "All devices in the virtual cluster must be on the same outside and inside IP subnets" but then, I have some slides from a Cisco Networkers training (26-29 Jan 2009) titled "Deploying Remote Access with SSL VPNs" written by Nadhem J. AlFardan where it sais that it is posible to configure two ASA one in London and one in New York in a cluster to provide load balancing between them.
Does anyone have configured load-balancing between two ASA not sharing the same outside and inside subnetworks? Is there any documentation addressing this issue?