Device management and management tool troubleshooting - Part I

In this section, we are working to cover the below topics.

Device management troubleshooting > issues related to console, vty access and remote transfer tools such as TELNET, SSH, TFTP, HTTP/S, and SCP

Management tool troubleshooting > various management tools such as SYSLOG, SNMP, Cisco IP SLA, object tracking, NetFlow and flexible NetFlow. In additional bidirectional forwarding detection (BFD) and troubleshoot network problems using Cisco DNA center assurance.

To troubleshooting a Cisco router, you have to log in to the device by using console cable to access them physically or via remote sessions with vty lines. If you are going to access a device due to management purpose or access fails, first of all, you need to investigate the cause of why the issue has happened and then do further troubleshooting other cases. Sometimes you need to copy backup files or upload IOS (Internetwork OS) to the router. To do that you have to use specific protocols. If you cannot access the router via the protocol, you also have to troubleshoot the case. Tools such as SYSLOG, SNMP can be used to get more information about the network and use that information to troubleshoot a problem.

Device Management Troubleshooting

When you need to access a router for a management purpose, you can log in to the router either physically via console cable or remote access via Telnet or SSH which means the device can access from a remote location. Whatever the issue which has to investigate or troubleshoot, you have to access the router. In addition, sometimes you have to transfer configuration files or upgrade the IOS image while troubleshooting a problem. You also have to consider remote transferring using various protocols such as TFTP, HTTP/S, and SCP. Furthermore, this chapter will explain why management access to router gets fail, why it occurs and how to fix the issue.

Console Access Troubleshooting

When you are trying to access a Cisco router or switch via console, you have to look below the setting for further troubleshooting.

Correct COM port selected in the terminal program? > Most of the time, many COM ports are showing the terminal program. However, the last one listed is the correct one use from a drop-down list according to our experience. If it fails, the problem-solving method is trial and error process. Then you have to have identified the correct COM port for your OS which you used the terminal program. For instance, Windows 10, you can identify COM port numbers in the device manager.

Terminal program settings are configured correctly? > Cisco devices use default values such as 9600 baud, 8 data bits, 1 stop bit, and no parity.

Line password used to authenticate to the console? > The Login command and line password are not configured by default. If the line password used, the login command would need to be configured.

Local username/password to authenticate to the console? > If authentication used, user credentials would exist in the local database and the login local command required on the line.

AAA server used to authenticate to the console? > If AAA authentication used, a method would need to be defined with login authentication {default | list_name} command inline console configuration mode.

Correct cable and drivers used to connect to the console port? > Check your document to verify what method is needed. Nowadays mini USB ports are supporting as a console port (drivers required on PC), whereas older devices have the capability to RJ-45 console (rollover cable). If your PC doesn’t have a serial port, you have to have a USB to serial cable to connect the console cable and the correct drivers on your PC to use it.

Next Part II - We will discuss about VTY access troubleshooting and so on. Subscribe our blog and keep in touch with latest articles.

Cheers!