Network technologies and trends » configuring Cisco Nexus 7000 Switch

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 allocate physical interfaces to VDC in a Cisco Nexus 7000 Series switch?

Yasir Irfan — Wed, 29 Dec 2010 05:27:46 +0000

To allocate physical interfaces to VDC from the config terminal mode type the VDC name and then allocate the physical interfaces as shown below by using the command “allocate interface”

N7000-ITKE01#configure t

N7000-ITKE01 (config)#vdc VDC-CORE1

N7000-ITKE01-DC-CORE1 (config-vdc)#allocate interface Ethernet1/1

N7000-ITKE01-DC-CORE1 (config-vdc)#allocate interface Ethernet1/2

N7000-ITKE01 -DC-CORE1 (config-vdc)#allocate interface Ethernet1/3

Now let’s verify the Interface allocation to the VDC by using following command ” show vdc membership”

N7000-ITKE01-DC-CORE1# show vdc membership

vdc_id:2 vdc_name: DC-CORE1 interfaces:
        Ethernet1/1           Ethernet1/2           Ethernet1/3
        Ethernet1/4           Ethernet1/5           Ethernet1/6
        Ethernet1/7           Ethernet1/8           Ethernet1/9
        Ethernet1/10          Ethernet1/11          Ethernet1/12
        Ethernet1/13          Ethernet1/14          Ethernet1/15
        Ethernet1/16          Ethernet1/17          Ethernet1/18
        Ethernet1/19          Ethernet1/20          Ethernet1/21
        Ethernet1/22          Ethernet1/23          Ethernet1/24
        Ethernet1/25          Ethernet1/27          Ethernet1/29
        Ethernet1/31

N7000-ITKE01-DC-CORE1#

In addition to interfaces other physical resources such as IPv4 router memory, IPv6 router memory, port-channels, SPAN sessions can be allocated to individual VDC.