you can use one of the following methods to allocate ip information to your switch (essential if you wish to manage your switch across the network).

    manual ip configuration

    you can choose to configure the ip information yourself. the switch remembers the information that you enter until you change it again or set the configuration method to automatic.

    you should use the manual ip configuration method if:

    you do not have a dhcp or bootp server on your network, or

    you want to remove the risk of the ip address ever changing, or

    your dhcp or bootp server does not allow you to allocate static ip addresses. (static ip addresses are necessary to ensure that the switch is always allocated the same ip information.)

    for most installations, 3com recommends that you configure the switch ip information manually. this makes management simpler and more reliable as it is not dependent on a dhcp or bootp server, and eliminates the risk of the ip address changing.

    if you wish to manually enter ip information for your switch, work through the "manually configuring ip information" section on page 31.

    automatic ip configuration

    by default the switch tries to configure itself with ip information without requesting user intervention. it tries to obtain an ip address from a dhcp or bootp server on the network.

    if neither server is found, the switch will configure itself with its default ip address 169.254.100.100 if it is operating in a standalone mode, and/or no other switches on the network have this ip address. if this default ip address is already in use on the network then the switch detects this and configures itself with an ip address in the range 169.254.1.0 to 169.254.254.255.

    this process is known as auto-ip and is the same mechanism used by windows 98 and windows 2000. ip addresses configured by auto-ip are temporary as they cannot be routed but are useful for small networks which are not connected to other networks, or for initial configuration.

    however, as soon as a dhcp or bootp server is detected, the switch will configure itself with the ip address allocated by that server.

    when using automatic ip configuration it is important that the ip address of the switch is static, otherwise you will not know what the ip address is and it will be difficult to manage. most dhcp and bootp servers allow static ip addresses to be configured so that you know what ip address will be allocated to the switch. refer to the documentation that accompanies your dhcp/bootp server.

    for a detailed description of how automatic ip configuration operates, please refer to the implementation guide on the cd-rom that accompanies your switch or on the 3com web site.

    you should use the automatic ip configuration method if:

    your network uses dhcp or bootp to allocate ip information, or

    flexibility is needed. if the switch is re-deployed onto a different subnet, it will automatically reconfigure itself with an appropriate ip address, instead of you having to manually reconfigure the switch.

    if you use the automatic ip configuration method, you need to discover the automatically allocated ip information before you can begin management. work through the "viewing automatically configured ip information" section on page 37.