Network technologies and trends » Cisco IOS Commands

Telnet by default disabled in NX-OS devices

Yasir Irfan — Wed, 23 Mar 2011 06:13:06 +0000

As I am working with Nexus 7000, Nexus 5000 and 2000 Series Switches, I discovered by default Telnet Server is disabled in a NX-OS devices such as Nexus 7000, Nexus 5000 and 2000 Series Switches.

We all know Telnet protocol enables TCP/IP connections to a host. Telnet allows a user at one site to establish a TCP connection to a login server at another site and then passes the keystrokes from one device to the other. Telnet can accept either an IP address or a domain name as the remote device address.

I will show you how to enable the Telnet Server in NX-OS devices

VDC-Admin(config)# feature telnet

VDC-Admin(config)# show telnet server

telnet service enabled

VDC-Admin(config)#

What happened to “write memory” IOS command in Cisco Nexus 7000 Series Switch?

Yasir Irfan — Wed, 05 Jan 2011 06:05:45 +0000

When configuring Cisco Catalyst Switches, I quite often use “write memory” command to save my configuration rather than using “copy running-configuration startup-configuration” Cisco IOS command. Other day I was saving my running configuration to the startup configuration in a Cisco Nexus 7000 Series Switch in the usual way ” wri mem”. But I got the following error

VDC-Admin-DC-AGG1# write memory
^
% Invalid command at ‘^’ marker.
VDC-Admin-DC-AGG1#

Now Cisco Nexus 7000 Series switch won’t support the “write memory” command. Rather you need to use the “copy running-configuration startup-configuration” to save your configuration. One more difference I figured out between Cisco IOS and NX-OS is the missing of “write memory” command.

VDC-Admin-DC-AGG1#
VDC-Admin-DC-AGG1# write ?
erase Destroys the configuration on persistent media

VDC-Admin-DC-AGG1# write

Now the time has come for me better start using “copy running-configuration startup-configuration” command in NX-OS based Cisco switches.

How to Determine the Serial Number of Supervisor Engine installed in a Cisco Catalyst 6500 Switch

Yasir Irfan — Sun, 24 May 2009 11:35:49 +0000

Imagine you have a Cisco Catalyst 6500 Switch, you were asked to figure out the Serial number for the Supervisor Engine Installed in your Cisco Catalyst 6500 Switch , it can done by using issuing the following command “show idprom module” as shown in the below example.

ITKE-DAC-6500-BB01#show idprom module 7

IDPROM for module #7

(FRU is ‘Supervisor Engine 720′)

OEM String = ‘Cisco Systems’

Product Number = ‘WS-SUP720-3B’

Serial Number = ‘SAD084608JG’

Manufacturing Assembly Number = ’73-9740-01′

Manufacturing Assembly Revision = ‘A0′

Hardware Revision = 4.0

Current supplied (+) or consumed (-) = -4.50A

ITKE-DAC-6500-BB01#