Load balancing (LB) is a cluster technology that distributes services among multiple network devices or links.

LB includes the following types:

• Server load balancing—Data centers generally use server load balancing for networking. Network services are distributed to multiple servers or firewalls to enhance the processing capabilities of the servers or firewalls.

• Link load balancing—Link load balancing applies to a network environment where there are multiple carrier links to implement dynamic link selection. This enhances link utilization. Link load balancing supports IPv4 and IPv6, but does not support IPv4-to-IPv6 packet translation. Link load balancing is classified into the following types based on the direction of connection requests:

  • Outbound link load balancing—Load balances traffic among the links from the internal network to the external network.

  • Transparent DNS proxy—Load balances DNS requests among the links from the internal network to the external network.