H3C Technologies H3C SecPath F1000-E - Manual (Page 850)

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Stateful Failover Configuration
Overview
Introduction to Stateful Failover
Some customers require the key entries or access points of their networks, such as the Internet access
point of an enterprise or a database server of a bank, to be highly reliable to ensure continuous data
transmission. Deploying only one device (even with high reliability) in such a network risks a single
point of failure and therefore cannot meet the requirement, as shown in Figure 1 .
Figure 1 Network with one device deployed
The stateful failover feature was introduced to meet the requirement. Stateful failover backs up services
such as NAT, ALG, portal, blacklist, DHCP server and load balancing, and synchronizes configurations
between two devices. In Figure 2 , two devices that are enabled with stateful failover are deployed in the
network. Each device has a failover interface. The failover interfaces are connected over the failover
link.
NOTE:
The failover link transmits only state negotiation messages and backup data.