Install more than one CSS replica in an organization.
Deploy CSS replicas on dedicated servers in large organizations, and on other multi-tasking servers such as Domain Controllers in mid-sized organizations.
Enable network load balancing for server redundancy.
Install the Enterprise version of ISA Server 2004 on Windows Server 2003 whenever possible.
Synchronize all the ISA Server clocks to an NTP time source to ensure that they are writing timestamps into logs accurately.