Answers

Figure 1: Two Routers with IP Addresses

Example 3: R1 Config

Example 4: R2 Config

Commentary

Syslog provides a mechanism on devices to log the messages that a specific device (system) will typically generate to the console. This provides engineers with the ability to look back at the history of device and the view the events that have happened to gain insight as to its current status. This mechanism accounts for Syslog’s widespread use in troubleshooting. It also provides a method of delivering these messages to an external Syslog server for central storage.

For this lab you were asked to alter the format of the Syslog messages. The two most used options include the use of sequence numbers as well as timestamps (Default) which enable system events to be correlated with other systems information. The service sequence-numbers and service timestamps global commands enable both; to disable them, use the same command with a no at the beginning.

The lab also asked that you configure the logging buffered command so that the router will buffer (store in memory) a copy of the log messages. Cisco devices typically use a default of keeping log messages in a buffer, but the examples show the command just to be complete as compared to the requirements in the lab.

Known Issues in this Lab

This section of each Config Lab Answers post hopes to help with those issues by listing any known issues with Packet Tracer related to this lab. In this case, the issues are:

Why Would Cisco Packet Tracer Have Issues?

(Note: The below text is the same in every Config Lab.)

Cisco Packet Tracer (CPT) simulates Cisco routers and switches. However, CPT does not run the same software that runs in real Cisco routers and switches. Instead, developers wrote CPT to predict the output a real router or switch would display given the same topology and configuration – but without performing all the same tasks, an actual device has to do. On a positive note, CPT requires far less CPU and RAM than a lab full of devices so that you can run CPT on your computer as an app. In addition, simulators like CPT help you learn about the Cisco router/switch user interface – the Command Line Interface (CLI) – without having to own real devices.

CPT can have issues compared to real devices because CPT does not run the same software as Cisco devices. CPT does not support all commands or parameters of a command. CPT may supply output from a command that differs in some ways from what an actual device would give. Those differences can be a problem for anyone learning networking technology because you may not have experience with that technology on real gear – so you may not notice the differences. So this section lists differences and issues that we have seen when using CPT to do this lab.

Beyond comparing your answers to this lab’s Answers post, you can test in Cisco Packet Tracer (CPT) or Cisco Modeling Labs (CML). In fact, you can and should explore the lab once configured. For this lab, once you have completed the configuration, try these verification steps. 

Although this lab shows a two-router lab, you could do it on a single router with a console connection.

1. Login from the console and then get into config mode and back out again. Each time you exit configuration mode, the router will issue a log message to the console about the fact that someone may have changed the configuration. So it is an easy way to generate log messages so that you can test your Syslog settings. Look at those messages to check the log message format to see if it meets the requirements of the lab.
2. Alternately, move to enable mode, enter configuration mode (configure terminal), and then exit configuration mode. Doing so will also generate log messages.