H3C Technologies H3C SecBlade LB Cards - Manual (Page 13)

7
Working mechanism of firewall load balancing
Firewall load balancing supports IPv4 and IPv6.
Figure 7 Network diagram
Firewall load balancing comprises the following elements:
• Cluster—A cluster consists of LB products and firewalls to provide network traffic load balancing.
• LB product—A device that distributes traffic from the request sender to multiple firewalls. LB products
fall into level 1 LB products and level 2 LB products. In
Figure 7 , if traffic is from Host A to Host B, LB
product A is level 1, and LB product B is level 2. If traffic is from Host B to Host A, LB product B is level
1, and LB product A is level 2.
• Firewall—A firewall filters packets.
Figure 8 Work flow of firewall load balancing
Firewall load balancing operates in the following way:
1. LB product A receives the traffic from the source.
(1) Traffic from source
LB product A Firewall
(3) Forward
LB product B
(2)
Scheduler & Forward
(4) Record &
Forward to destination
(5) Traffic from destination
(7) Forward
(8) Forward to source
(6) Forward