Loopback Interface Configuration Mode Commands


Loopback Interface Configuration Mode Commands
 
 
The Loopback Interface Configuration Mode is used to create and manage loopback interfaces that provide IP addresses that are always available and reachable from any interface within the same given context.
 
Important: The commands or keywords/variables that are available are dependent on platform type, product version, and installed license(s).
 
description
Configures the description text for the current interface.
Product
All
Privilege
Security Administrator, Administrator
Syntax
description text
no description
no
Clears the description for the interface.
text
Specifies the descriptive text to use. text must be 0 to 79 alpha and/or numeric characters with no spaces or a quoted string of printable characters
Usage
Set the description to provide useful information on the interface’s primary function, services, end users, etc. Any information useful may be provided.
Example
description sampleInterfaceDescriptiveText
 
end
Exits the interface configuration mode and returns to the Exec mode.
Product
All
Privilege
Security Administrator, Administrator
Syntax
end
Usage
Change the mode back to the Exec mode.
 
exit
Exits the interface configuration mode and returns to the context configuration mode.
Product
All
Privilege
Security Administrator, Administrator
Syntax
exit
Usage
Return to the context configuration mode.
 
ip address
Configures the IP options for the current interface.
Product
All
Privilege
Security Administrator, Administrator
Syntax
ip address {ip_address ip_mask | ip_address/bitmask} [secondary | srp-activate]
no ip address ip_address
no
Deletes the specified IP address from the interface configuration.
address {ip_address ip_mask | ip_address/bitmask} [secondary | srp-activate]
Configures the IP address and network mask for the interface.
ip_address ip_mask specifies an IP address and the subnet mask pair which is used to identify the IP address of the interface. ip_address must be specified using the standard IPv4 dotted decimal notation. Currently, the only value accepted for ip_mask is 255.255.255.255.
ip_address/net_mask : the IP address and the length in bits of the network mask. This must be an IP address entered in dotted decimal notation and a mask (192.168.1.0/32). Currently, the only value accepted for bit_mask is 32.
The secondary keyword is used to configure a secondary IP address on the interface. This is referred to as multi-homing of the interface.
The srp-activate keyword activates the IP address for Interchassis Session Redundancy.
Usage
Create and manage loopback interfaces for the current context.
Example
The following command configures IP address to associate with the interface:
ip address 1.2.3.4 255.255.255.255
The following command removes the associated IP address for the interface:
no ip address 1.2.3.4
 
ip vrf
This command configures the IP VPN Routing/Forwarding instance for the current interface.
Product
All
Privilege
Security Administrator, Administrator
Syntax
ip vrf forwarding vrf_name
no vrf forwarding
no
Deletes the specified IP VPN routing/forwarding instance from the interface configuration.
vrf_name
Specifies the preconfigured IP VPN routing/forwarding instance name which is to be used with this interface.
vrf_name must be a preconfigured VPN routing/forwarding instance name with ip vrf forwarding command in Context Configuration Mode.
Usage
Use this command to associate a preconfigured IP VPN Routing/Forwarding instance for the current interface.
Example
The following command associates a preconfigured IP routing/forwarding instance named vrf_1 with this interface:
ip vrf forwarding vrf_1
 
ipv6 address
Configures the IPv6 options for the current interface.
Product
All
Privilege
Security Administrator, Administrator
Syntax
ipv6addressipv6_address ip_mask [ srp-activate ]
no iv6paddressipv6_address
no
Deletes the specified IPv6 address from the interface configuration.
address ipv6_address ip_mask [ srp-activate ]
Configures the IP address and network mask for the interface.
ipv6_address ip_mask specifies an IP address and the subnet mask pair which is used to identify the IPv6 address of the interface. ipv6_address must be specified using the standard IPv6 dotted decimal notation.
The srp-activate keyword activates the IPv6 address for Session Recovery.
Usage
Create and manage loopback interfaces for the current context and enable Session Redundancy Protocol (SRP) when appropriate.
Example
The following command configures an IPv6 address to associate with the interface and enables SRP:
ipv6 address 2001:268:2008:b::1021/128 srp-activate
 
 

Cisco Systems Inc.
Tel: 408-526-4000
Fax: 408-527-0883