Users Guide

INTERFACE mode
ip address ip-address mask [secondary]
• ip-address mask: enter an address in dotted-decimal format (A.B.C.D). The mask must be in slash format (/24).
• secondary: the IP address is the interface’s backup IP address. You can congure up to eight secondary IP addresses.
Example of a Conguration for a VLAN Participating in an OSPF Process
interface Vlan 10
ip address 1.1.1.2/24
tagged GigabitEthernet 2/2-2/13
tagged GigabitEthernet 5/1
ip ospf authentication-key force10
ip ospf cost 1
ip ospf dead-interval 60
ip ospf hello-interval 15
no shutdown
!
Loopback Interfaces
A Loopback interface is a virtual interface in which the software emulates an interface. Packets routed to it are processed locally.
Because this interface is not a physical interface, you can congure routing protocols on this interface to provide protocol stability. You can
place Loopback interfaces in default Layer 3 mode.
To congure, view, or delete a Loopback interface, use the following commands.
• Enter a number as the Loopback interface.
CONFIGURATION mode
interface loopback number
The range is from 0 to 16383.
• View Loopback interface congurations.
EXEC mode
show interface loopback number
• Delete a Loopback interface.
CONFIGURATION mode
no interface loopback number
Many of the commands supported on physical interfaces are also supported on a Loopback interface.
Null Interfaces
The Null interface is another virtual interface. There is only one Null interface. It is always up, but no trac is transmitted through this
interface.
To enter INTERFACE mode of the Null interface, use the following command.
• Enter INTERFACE mode of the Null interface.
CONFIGURATION mode
interface null 0
The only congurable command in INTERFACE mode of the Null interface is the ip unreachable command.
Interfaces
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