Technical data
May 31, 2012 © 2012 Brocade Communications Systems, Inc. 3 - 1
Chapter 3
ServerIron FWLB Overview
Firewall Load Balancing (FWLB) allows the ServerIron to balance traffic on multiple firewalls. The ServerIron
supports the following FWLB topologies: Basic FWLB, High Availability (HA) FWLB, and Multizone FWLB.
NOTE: The ServerIron does not currently support the following topologies: FWLB + NAT, FWLB + Layer 7, FWLB
+ SYN Proxy.
This chapter contains the following sections:
• “Understanding ServerIron FWLB” on page 3-1
• “Basic FWLB Topology” on page 3-6
• “HA FWLB Topology” on page 3-7
• “Multizone FWLB Topology” on page 3-9
Understanding ServerIron FWLB
This section contains the following sections:
• “Firewall Environments” on page 3-1
• “Load Balancing Paths” on page 3-2
• “Firewall Selection” on page 3-3
• “Hashing Mechanism” on page 3-4
• “Firewall with Fewest Sessions” on page 3-4
• “Health Checks” on page 3-4
Firewall Environments
ServerIron supports load balancing across the following firewall environments:
• “Synchronous Firewall Environments” on page 3-2
• “Asynchronous Firewall Environments” on page 3-2
• “NAT Firewall Environments” on page 3-2
• “Dynamic Route Environments” on page 3-2