User's Manual

2-6
Cisco CSR 1000V Series Cloud Services Router Software Configuration Guide
OL-27477-07
Chapter 2 Using Cisco IOS XE Software
Using the no and default Forms of Commands
Using the no and default Forms of Commands
Almost every configuration command has a no form. In general, use the no form to disable a function.
Use the command without the no keyword to re-enable a disabled function or to enable a function that
is disabled by default. For example, IP routing is enabled by default. To disable IP routing, use the no
ip routing command; to re-enable IP routing, use the ip routing command. The Cisco IOS XE software
command reference publications provide the complete syntax for the configuration commands and
describe what the no form of a command does.
Many CLI commands also have a default form. By issuing the command default command-name, you
can configure the command to its default setting. The Cisco IOS XE software command reference
publications describe the function of the default form of the command when the default form performs
a different function than the plain and no forms of the command. To see what default commands are
available on your system, enter default ? in the appropriate command mode.
Saving Configuration Changes
Use the copy running-config startup-config command to save your configuration changes to the startup
configuration so that the changes will not be lost if the software reloads or a power outage occurs. For
example:
Router# copy running-config startup-config
Building configuration...
Router(config-if)# ip address 172.16.0.1 ?
A.B.C.D IP subnet mask
Router(config-if)# ip address 172.16.0.1
Enter the keyword or argument that you
want to use. This example uses the
172.16.0.1 IP address.
Enter ? to display what you must enter
next on the command line. In this
example, you must enter an IP subnet
mask.
A <cr> is not displayed; therefore, you
must enter additional keywords or
arguments to complete the command.
Router(config-if)# ip address 172.16.0.1 255.255.255.0 ?
secondary Make this IP address a secondary address
<cr>
Router(config-if)# ip address 172.16.0.1 255.255.255.0
Enter the IP subnet mask. This example
uses the 255.255.255.0 IP subnet mask.
Enter ? to display what you must enter
next on the command line. In this
example, you can enter the secondary
keyword, or you can press Enter.
A <cr> is displayed; you can press
Enter to complete the command, or
you can enter another keyword.
Router(config-if)# ip address 172.16.0.1 255.255.255.0
Router(config-if)#
In this example, Enter is pressed to
complete the command.
Table 2-5 Finding Command Options (continued)
Command Comment