Contents

Load balancing overview·· 1

Restrictions and guidelines· 1

Advantages of load balancing· 1

Load balancing types· 1

Load balancing overview

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

Restrictions and guidelines

You must enable session statistics collection for hardware fast forwarding on devices that support hardware fast forwarding. If you do not enable the function, load balancing statistics are inaccurate, and all statistics-collection-related features are affected. Specifically, the following will be affected:

Link bandwidth statistics.

Packet count statistics.

Bandwidth algorithm.

Maximum bandwidth algorithm.

Link protection feature.

For information about session statistics collection for hardware fast forwarding, see session management configuration in Security Configuration Guide.

Advantages of load balancing

Load balancing has the following advantages:

High performance—Improves overall system performance by distributing services to multiple devices or links.

Scalability—Meets increasing service requirements without compromising service quality by easily adding devices or links.

High availability—Improves overall availability by using backup devices or links.

Manageability—Simplifies configuration and maintenance by centralizing management on the load balancing device.

Transparency—Preserves the transparency of the network topology for end users. Adding or removing devices or links does not affect services.

Load balancing types

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. (This type is not supported in the current software version.)

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.

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

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