Cisco – IT Blog

How to change MTU on Cisco

I will give an example of increasing MTU on Cisco switches.

Debug on Cisco

In this article, I will give an example of configuring and viewing debug information on Cisco switches. For an example and a test, I will take a Cisco Catalyst 6509-E switch.

How to configure time (NTP) on Cisco

In this article, I’ll give an example of setting time and setting NTP to automatically synchronize time on Cisco switches.

Cisco 6509e Net Input CPU Load

Once on a single Cisco 6509e switch configured as L3 and with a standard CPU load of 10%, the load suddenly increased to 40%.

Configuring Cisco Catalyst 6509-E

Using an example, I will configure the Cisco Catalyst 6509-E with firmware 12.2 (33) SXJ7.
And so, connect to the console port, the standard speed is 9600 bps, 8N1.

Example of commands to view information about firmware and hardware:

Cisco Catalyst 6500 Management Access Restriction

To limit access to the management of the Cisco Catalyst 6500, first we make an access-list with IP addresses from which we will later allow us to connect to the device via SNMP, telnet, etc.:

Configuring Cisco Catalyst 2960

On the test I will configure Cisco Catalyst WS-C2960-24TT-L with firmware 12.2(25)FX

Red SYSTEM LED on SW-SUP720-3BXL

Once on a Cisco Catalyst 6509-E, I noticed that the SYSTEM LED on the WS-SUP720-3BXL is lit red.

Online diagnostics Cisco Catalyst 6500

In this article, I will describe the Cisco Catalyst 6500 online diagnostic commands.

WS-SUP720-3BXL does not start Not Applicable Unknown

Once after a power outage, on Cisco Catalyst 6509-E, instead of the main module WS-SUP720-3BXL, only the backup module was launched.
As I found out later, the memory card stopped working and, accordingly, the module could not start the firmware. At this moment on the module all the indicators glowed red.