Service Manual

A consideration for including VLANs in routing protocols is that you must configure the no shutdown
command. (For routing traffic to flow, you must enable the VLAN.)
NOTE: You cannot assign an IP address to the default VLAN, which is VLAN 1 (by default). To assign
another VLAN ID to the default VLAN, use the default vlan-id vlan-id command.
To assign an IP address to an interface, use the following command.
• Configure an IP address and mask on the interface.
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 configure up to eight
secondary IP addresses.
Example of a Configuration for a VLAN Participating in an OSPF Process
interface Vlan 10
ip address 1.1.1.2/24
tagged TenGigabitEthernet 2/2-13
tagged TenGigabitEthernet 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 configure routing protocols on this interface to
provide protocol stability. You can place Loopback interfaces in default Layer 3 mode.
To configure, 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 configurations.
EXEC mode
show interface loopback number
• Delete a Loopback interface.
CONFIGURATION mode
no interface loopback number
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Interfaces