This chapter provides an overview of how FortiGate-6000 Session-Aware Load Balancing (SLBC) works and then breaks down the details and explains why you might want to change some load balancing settings.
|For information about IPsec load balancing, see FortiGate-6000 IPsec VPN.|
FortiGate-6000 SLBC works as follows.
SLBC attempts to match all incoming sessions with a configured flow rule (see Load balancing and flow rules). If a session matches a flow rule, the session is directed according to the action setting of the flow rule. Usually flow rules send traffic that can't be load balanced to a specific FPC.
TCP, UDP, SCTP, ICMP (IPv4 only) and ESP (IPv4 only) sessions that do not match a flow rule are directed to the DP3 processors.
The DP3 processors distribute sessions to the FPCs according to the load balancing method set by the
dp-load-distribution-methodoption of the
config load-balance settingcommand.
All other sessions are sent to the primary (or master) FPC.