Appendix A: Diagnostics

Overview

Several different types of diagnostic tools are provided, with output accessible in either the web or command-line interface, or as files sent to a remote location.

These tools include:

• Event Manager--the CNA decision-maker process sends data packets to other CNA processes in response to various events; the event-manager process listens for these packets and forwards them to their intended recipients, and to a control panel in the web interface, an internal event log, and, if enabled, a CLI-session terminal
• Show Commands--more than two dozen show commands are available, generating tables of statistics detailing such things as routing tables, system logs, internal statistics, and diagnostic data; output is available from both the command line and the web interface
• Other CLI Commands--CNA implements some standard network diagnostic utilities, including ping, traceroute, and tcpdump, plus a logging mechanism that allows you to forward log messages to a remote Syslog system
• Medic--CNA includes an internal monitoring and error-recovery process called Medic; this process constantly evaluates the state of various internal processes and, when necessary, can administer corrective action to recover from abnormal conditions