The first packet that’s copied to the NetFlow cache contains all security and routing information. If policy networking (such as an access list) is applied to an interface, the first packet is matched to the list criteria. If there is a match, the cache is flagged so that any other packets arriving with the flow can be switched without being compared to the list.

Note NetFlow switching can be configured on most 7000 series router interfaces and can be used in a switched environment. NetFlow switching can also be configured on VIP interfaces.

System Message Logging

The system message logging software can save messages to a log file or direct the messages to other devices. By default, the switch logs normal but significant system messages to its internal buffer and sends these messages to the system console. You can access logged system messages using the switch CLI or by saving them to a properly configured syslog server.

System logging messages are sent to console and Telnet sessions based on the default logging facility and severity values. You can disable logging to the console or logging to a given Telnet session. When you disable or enable logging to console sessions, the enable state is applied to all future console sessions. In contrast, when you disable or enable logging to a Telnet session, the enable state is applied only to that session.

Most enterprise network configurations include a Unix−based or Windows−based system log server to log all messages from the devices in the network. This server provides a central location from which you can extract information about all the devices in the event of a network failure or other issue. You can use several set logging commands. Let’s take a look at those that will not be covered in the Immediate Solutions section and what each will do:

∙set logging server—Specifies the IP address of one or more syslog servers. You can identify up to three servers.

∙set logging server facility—Sets the facility levels for syslog server messages.

∙set logging server severity—Sets the severity levels for syslog server messages.

∙set logging server enable—Enables system message logging to configured syslog servers.

Loading an Image on the Supervisor Engine III

Trivial File Transfer Protocol (TFTP) boot is not supported on the Supervisor Engine III or on either the Catalyst 4000 series and the 2948G switch Supervisor Engine modules. You can use one of two commands to load a saved image. To load copies to a TFTP server, use the following:

copy file−ld tftp

To load copies to Flash memory, use the following:

copy file−ld flash

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