1.1 Analyzing IP Address Scenarios

Whenever a server's IP address changes, the following problems occur:

Until now, the workaround was to manually modify the configuration files of each application with the new IP address. Some of you might have opted to reinstall the server.

Port conflicts occur when there are multiple applications contending for the same port, IP address, and protocol combination. Even here, the workaround was to manually modify the configuration files of each application with the new IP address. Again, some of you might have opted to reinstall the server.

This section further discusses the following:

1.1.1 Scenarios for IP Address Configuration Changes

This section discusses the scenarios that you might encounter when you need to change the IP address of a server.

When Applications Bind to a Wildcard Address (0.0.0.0)

Applications that bind to a wildcard address (INADDR_ANY) are bound to 0.0.0.0. These applications use any available IP address for connections; such applications continue to work without any problem when the IP address on the system is changed.

When Applications Bind to a Specific Address

These applications bind only to a specific IP address. When this address is changed, these applications stop working. These applications do not work even after they are reloaded or the server is restarted.

When Applications Bind to a Nonspecific Address (Default IP)

These applications do not care which IP address they are listening to as long as they connect to one of the IP addresses on the server.

NOTE:If a default IP address is not configured, the TCP/IP stack assigns the first bound IP address on the server as the default IP address.

To configure the default IP address, refer to the OES 2: Novell TCP/ IP for NetWare Administration Guide

1.1.2 Scenarios for Port Conflicts

This section discusses the scenarios related to port conflicts during IP Address: Portl.c. on “address” and “port” configuration changes.

When Applications Compete for Ports

When multiple applications contend for the same port: IP address: protocol combination, this results in port conflicts. Port conflicts can be resolved by using either a different port or a different IP address.

When Applications Do Not Compete for Ports

Applications that do not compete for ports toggle between the valid and invalid status. These applications have their ports marked as N/A.