Determining which applications to use with Network Load Balancing

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Determining which applications to use with Network Load Balancing

Many applications work with Network Load Balancing. This section offers guidelines for determining which applications might be suitable.

In general, Network Load Balancing can load balance any application or service that uses TCP/IP as its network protocol and is associated with a specific Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) port. For more information, see Transmission Control Protocol (TCP) and User Datagram Protocol (UDP).

Some examples are:

Protocol Examples

HTTP over TCP/IP

Web servers, such as Microsoft Internet Information Services: Port 80.

HTTPS over TCP/IP

HTTP over SSL (Secure Sockets Layer), for encrypting Web traffic: Port 443.

FTP over TCP/IP

FTP (File Transfer Protocol): Port 20, port 21, and ports 1024-65535.

TFTP over TCP/IP

TFTP servers (used by such applications as BOOTP): port 69.

SMTP over TCP/IP

SMTP (Simple Mail Transfer Protocol), used by such applications as Microsoft Exchange: Port 25.

RDP over TCP/IP

RDP (Remote Datagram Protocol), used by Terminal Services: Port 3389.

In addition, Network Load Balancing is in common use with:

  • Web servers using round-robin DNS.

  • Virtual private network (VPN) servers.

  • Streaming media servers.

  • Print Services.

  • Microsoft Internet Security and Acceleration Server (ISA).