Concept Guide
NOTE: You cannot simultaneously use egress rate shaping and ingress rate policing on the same VLAN.
The system supports Inter-VLAN routing (Layer 3 routing in VLANs). You can add IP addresses to VLANs and use them in routing protocols
in the same manner that physical interfaces are used. For more information about conguring dierent routing protocols, refer to the
chapters on the specic protocol.
A consideration for including VLANs in routing protocols is that you must congure the no shutdown command. (For routing trac to
ow, 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.
• Congure 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 congure up to eight secondary IP addresses.
Example of a Conguration 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 5/0
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 congure routing protocols on this interface to provide protocol stability. You can
place Loopback interfaces in default Layer 3 mode.
To congure, 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 congurations.
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.
Interfaces
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