Port Rules

Each port rule configures load-balancing for client requests that use the port or ports covered by the Port Range parameter. How you load-balance your applications is mostly defined by how you add or modify port rules, which you create on each host for any particular port range.

For information about port assignments for common applications, such as HTTP and FTP, see Windows 2000 Network Load Balancing Help. For a complete list of TCP and UDP port assignments, see "TCP and UDP Port Assignments" in the Microsoft ® Windows ®  2000 Server Resource Kit TCP/IP Core Networking Guide .

Port Range

To load-balance all client requests with a single port rule, use the default port range (0-65535). By using the default port range, you do not have to worry about which port or ports are associated with the application whose client requests you are load-balancing.

Note

For Windows Load Balancing Service on clusters that are running Windows NT version 4.0, the default port range was 1-65535. Make sure to check default port-range values when you build mixed Windows NT 4.0/Windows 2000 clusters or when you perform rolling upgrades from Windows NT 4.0 to Windows 2000.

To specify a single port, enter the same port number for both the start and the end of the range — for example, 80-80.

You might need to use multiple port rules if you load-balance multiple applications with multiple policies. For example, you might set client affinity for one application but not for another.

If you use multiple port rules, make sure that for a specific port rule, the port range covers all the ports that the application uses; protocols such as FTP use more than one port.

Each port rule configures port ranges only for contiguous port numbers. Therefore, in rare circumstances (for example, if one application is associated with two noncontiguous sets of ports, between which there is an intervening port that another application uses) you might have to define more than one port rule for the application that uses the noncontiguous ports. For example, HTTP requests (and therefore most Web requests) use port 80, and Secure Sockets Layer (SSL) requests use port 443.

Protocols

Some applications (such as streaming media applications) use both TCP and UDP ports. In most scenarios, set the Protocols parameter to Both .