Creating a Configuration File

You can create a configuration file to configure the Catalyst 2900. The file contains all the commands necessary to configure the switch. Then, you upload the file to the network using the write network command. Finally, you use the configure network command to activate the file and configure the switch.

The purpose of the configuration file is to aid the set up of multiple Catalyst 2900s. For example, you might want to download the same configuration file to Catalyst 2900 that have the same hardware configuration so that they have identical module and port configurations. Some commands can be added to the configuration file to aid setting up multiple switches. For example, you can use the clear trunk all command followed by commands for setting trunk configuration. In this way, you can make sure to purge any existing configuration before writing the new configuration. Some administration information tables cannot be cleared, for example, the IP alias table, command alias, and snmp trap table. Instead, the table entries are merged when compatible and updated when conflicts occur.

Use the write network command to upload the configuration file to the network in a format that can be used by the configure network command. Refer to the write, show config, and write config commands in the "Switch Command Reference" chapter for examples.

When creating the configuration file, you must enter the commands in a logical way so that the system can respond appropriately. Use the following guidelines when creating a configuration file:

• If no passwords have been established, you must establish them using the set password and set enablepass commands. Enter a blank line after the set password and set enablepass commands. The passwords are saved in the configuration file as clear text.

If passwords exist, you cannot use the set password and set enablepass commands because the password verification will fail. If you enter passwords into the file, the switch will attempt to execute the intended new passwords as commands as it executes the file.

• Enter a blank line after each occurrence of the following commands:

  • set interface sc0 ip_addr netmask

  • set interface sc0 disable

  • set module disable mod_num

  • set port disable mod/_numport _num

A blank line is necessary because these commands might disconnect your Telnet session(s). Before disconnecting a session, the switch prompts for confirmation. Entering Return (designated by the CR on the blank line) indicates a negative response, which retains the Telnet session.

We recommend that you use a configuration file to configure Catalyst 2900 through the EIA/TIA-232 sessions. If you configure the switch from the Telnet session, IP addresses are not changed, and ports and modules are not disabled.