Configuring ROM

ROM monitor is a ROM−based program that can be configured to execute upon the following conditions:

∙Upon boot−up

∙Upon recycling the switch power

∙When a fatal exception error occurs

∙When the switch fails to find a valid system image

∙If the nonvolatile RAM (NVRAM) configuration is corrupt

∙If the configuration register is set to enter ROM monitor mode

The ROM monitor CLI is present only on the Supervisor Engine III, Catalyst 4000, and the 2948G series switch Supervisor Engine modules. When the switch is in the ROM monitor mode, the switch will allow you to load a system image manually from Flash memory, from a Trivial File Transfer Protocol (TFTP) file, or from the bootflash.

Entering ROM Configuration Mode

You can enter ROM configuration mode by using one of these two methods:

∙Cycle the power on the switch and press the Break key during the first 60 seconds of startup. (The Break key is enabled for the first 60 seconds after cycling the power on the switch.)

∙Enter ROM mode through a terminal server, using Telnet or another terminal emulation program. Enter the break command as soon as the power is cycled on the switch.

ROM monitor has its own unique prompt that informs you when you have entered ROM monitor mode. The prompt you will see when you have entered ROM configuration mode is rommon>.

Booting ROM Mode from a Flash Device

To boot from a flash device, you can use the following syntax, which is shown in Table 2.9:

boot [−xv] [device][imagename]

Table 2.9 : The boot command syntaxes.

The image name is optional. If no image name is presented, the system defaults to the first valid file in the device. Remember that file names are case sensitive. Let’s look at an example of using this command:

rommon> boot −x bootflash:cat5000−sup2.2−2.bin CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC Uncompressing file:

#######################################################################

#######################################################################

#######################################################################

50

Configuring SNMP

RMON works in conjunction with SNMP and requires a protocol analyzer or probe to use its full features. To use SNMP−based monitoring, you need to verify that SNMP is running on your IOS−based switch.

1. Verify that SNMP is running, using the following command in User or EXEC mode:

show snmp

2.Enable SNMP and allow read−only access to hosts using the public SNMP string by using this command in Configuration mode:

snmp−server community public

3.After enabling SNMP, you need to define a host IP address to send SNMP trap messages. Here is an example:

snmp server host 130.77.40.05 public

Configuring RMON

To configure RMON, use the following steps:

1.To show RMON statistics on a certain interface, use the following command:

show rmon statistics

This command shows statistics for the number of packets, octets, broadcast packets, and multicast packets received, as well as errors detected and packet lengths received.

2. Configure the SNMP community using this command:

set snmp community <read−only|read−write|read−write−all> <community string>

3. Assign the SNMP log server responsible for receiving traps with this command:

set snmp trap <hostaddress> <community−string>

Configuring RMON on a Set/Clear−Based Interface

To configure RMON on a Set/Clear−based interface, perform the following steps:

1. On a Set/Clear command−based interface, configure the SNMP community using this command:

set snmp community <read−only|read−write|read−write−all> <community string>

2. Assign the SNMP log server responsible for receiving traps with the following command:

set snmp trap <hostaddress> <community−string> Enable snmp with "set snmp enable"

Console> (enable) set snmp rmon enable SNMP RMON support enabled.

Console> (enable) show snmp

51