> Loopback Interface Configuration Mode Commands
> Use the Loopback Interface Configuration mode to create and manage loopback interfaces that provide IP addresses that are always available and reachable from any interface within a given context.
> Important: The commands or keywords/variables that are available are dependent on platform type, product version, and installed license(s).
> description
> Use this command to configure the descriptive 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. For text, enter 0 to 79 alpha and/or numeric characters with no spaces, or a string of printable characters within quotes.
> Usage
> Set the description to provide any useful information on the interface’s primary function, services, end users.
> Example
> description sampleInterfaceDescriptiveText
> end
> Enter this command to exit the interface configuration mode and return to the Exec mode.
> Product
> All
> Privilege
> Security Administrator, Administrator
> Syntax
> end
> Usage
> Change the mode back to the Exec mode.
> exit
> Enter this command to exit the interface configuration mode and return to the context configuration mode.
> Product
> All
> Privilege
> Security Administrator, Administrator
> Syntax
> exit
> Usage
> Return to the context configuration mode.
> ip address
> Use this command to configure 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 IP address you specify 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.
> Enter an ip_address ip_mask to specify an IP address and the subnet mask pair that identifies the IP address of the interface. For ip_address, specify with standard IPv4 dotted decimal notation. Currently, the only value accepted for ip_mask is 255.255.255.255.
> For the network mask, ip_address/net_mask, enter the IP address and the length in bits of the network mask in dotted decimal notation and a mask (192.168.1.0/32). Currently, the only value accepted for bit_mask is 32.
> Use the secondary keyword ito configure a secondary IP address on the interface. This is referred to as multi-homing of the interface.
> Use the srp-activate keyword to activate the IP address for Interchassis Session Recovery (ICSR).
> 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
> Use this command to configure 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 IP VPN routing/forwarding instance you specify from the interface configuration.
> vrf_name
> Specifies the preconfigured IP VPN routing/forwarding instance name to be used with this interface.
> For vrf_name, enter a preconfigured VPN routing/forwarding instance name with the 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
> Use this command to configure the IPv6 options for the current interface.
> Product
> All
> Privilege
> Security Administrator, Administrator
> Syntax
> ipv6 address ipv6_address ip_mask [ srp-activate ]
> no iv6p address ipv6_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 that identifies the IPv6 address of the interface. Specify ipv6_address in 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

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