F5 BIG-IP Load Balancer Design and Implementation (Windows SharePoint Services 2.0)

SharePoint 2003

Updated: 08-22-2005

F5 BIG-IP devices support 100 Mbps or 1 Gbps interfaces. For this deployment, 100 Mbps NIC cards are used on the BIG-IP devices.

A pair of BIG-IP load balancers (redundant BIG-IP controllers) supports automatic failover and helps insure the reliability of the request routing. The load balancing device pair is configured in the Active/Passive mode. Each F5 BIG-IP controller has two interfaces, exp0 (with public addresses) and exp1 (with private addresses).


Exp1 is the administrative interface. IP addresses for the BIG-IP controller are placed on exp1.

F5 BIG-IP IP Addresses

  • External Interface (exp0): Active IP address and Standby IP address

  • Internal Interfaces (exp1): Active IP address and Standby IP address

The state mirroring feature allows the standby unit to maintain all of the current connection and persistence information. If the active unit fails and the standby unit takes over, all connections continue, virtually uninterrupted.

Windows SharePoint Services automatically supports dynamic load balancing between front-end Web servers. There is no need to enable persistence on the BIG-IP controllers.

BIG-IP NAT/SNAT Configuration

Network Address Translation (NAT) is used to convert public address space (200.100.1. x ) to private address space (172.16.1. y ); for example, Windows SharePoint Services may connect to the Internet to retrieve additional Web Part information. Using Secure Network Address Translation (SNAT) provided by BIG-IP helps protect the internal network address information. The SNAT address for outbound traffic is Use Address Resolution Protocol (ARP) with NAT.

F5 BIG-IP Device Administration and Configuration

The Internet Platform and Operations group used and and logged in with the appropriate account and password to manage the BIG-IP controllers and load balancing configuration. To help provide a high level of security, they blocked traffic coming from the Internet and allowed only servers on the corporate network using the corporate proxy servers to access those two URLs.