Cisco

Cisco provide a gargantuan amount of documentation for their products, and a lot are available as straight PDF’s direct from Cisco.

In these guides are some useful commands for general maintenance, monitoring on Cisco switches.

packetlife.net is a great site to follow with regular hints, tips on improving your network layout, as well as maintaining and keeping your Cisco systems up and running.

Connecting to a Cisco Switch

There are two acceptable methods for connecting to a Cisco Switch, either through SSH (if enabled on the switch) or directly through the console port.

When connecting your terminal software make sure to rotate through terminal speeds starting with at minimum 9600.The default terminal speed configuration of a Cisco Router is probably 9600 8N1 but other configurations may have been set such as: 115200 8N1.

Administrator Prompt

The console command-line uses two prompts, the

Admin access is always available using ‘enable’ from the terminal/console connection (or after connecting with a valid ssh user/password.)

>
> enable
# 

‘enable’ behaves similarly to su root in Unix. Without it, you’re privileges are mostly limited to a subset “show” commands.

###Configuration

The Cisco switch holds two configurations, the running-config and the startup-config. The running-config is the (potentially unsaved) config currently running, and the startup-config is the persistent configuration that the device starts with.

# show running-config
# show startup-config

You can make the current configuration persistent by copying the running-config to the startup-config:

# copy running-config startup-config

The Cisco Switch Configuration text files are simply ascii command-line instructions to recreate a configuration. An example manual configuration of the console/terminal connection is shown below

# config terminal
(config)# line con 0
(config)# exec-timeout 60 0
(config)# no modem enable
(config)# length 100
(config)# transport preferred none
(config)# speed 115200
# end
# copy running-config startup-config
# show running-config

Archiving Configurations

After configuring the device with an IP address, it is convenient to edit the configuration locally on your desktop, and copy it accross to the switch every so often as you work:

Copy the running config to an sshd host

copy running-config scp:

Copy the edited / text from a http host

config replace http://10.0.0.2:9000/cisco01-config

Displaying Running Configurations

Runtime monitoring with the ‘show’ command, some interesting options

Useful Commands

# config term
(config)# enter configuration commands
...
...
(config)# end

Revert to the startup configuration using router replace.

# router replace nvram:startup-config