Troubleshooting Your CNA System

Assuming that your edge-router-to-ISP connection is configured properly and your edge router is able to peer with your service provider, there are several distinct areas to troubleshoot if your device is not receiving measurements from the Internet at large.

• You should be sure the connections between the CNA system and the edge router are configured correctly. The engine module needs to peer with your edge router to receive BGP updates, and your USTATs need to be able to send packets to and receive packets from the Internet or your active probe targets through your edge routers.
• Check to be sure that you have configured all required static routes on your router so that it knows where to locate the USTAT VIP addresses.
• If you are optimizing web traffic, you should also be sure you have configured your DNS server correctly so that random web hits are distributed correctly to your USTATs.

You can use the CNA implementations of the standard network debugging utilities ping, tcpdump, and traceroute to verify connectivity both on the CNA system (module to module) and between the CNA system and your edge router. Use your router’s implementation of these same utilities to view what happens to the traffic off the CNA system.

Other tools that you may find useful are log messages (see Messaging System in Appendix A: Diagnostics of the CNA Appendices Guide) and output of various show commands (see the CNA Command Reference Guide).