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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
Many of the same commands found in the physical interface are also found in the Loopback interfaces.
For more information, refer to Access Control Lists (ACLs).
Null Interfaces
The Null interface is another virtual interface. There is only one Null interface. It is always up, but no traffic 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 configurable command in INTERFACE mode of the Null interface is the ip unreachable command.
VLAN Membership
A virtual LAN (VLANs) is a logical broadcast domain or logical grouping of interfaces in a LAN in which all data received is kept
locally and broadcast to all members of the group. In Layer 2 mode, VLANs move traffic at wire speed and can span multiple
devices. Dell Networking OS supports up to 4093 port-based VLANs and one default VLAN, as specified in IEEE 802.1Q.
VLAN provide the following benefits:
Improved security because you can isolate groups of users into different VLANs.
Ability to create one VLAN across multiple devices.
On an Aggregator in standalone mode, all ports are configured by default as members of all (4094) VLANs, including the
default VLAN. All VLANs operate in Layer 2 mode. You can reconfigure the VLAN membership for individual ports by using the
vlan tagged or vlan untagged commands in INTERFACE configuration mode (Configuring VLAN Membership). Physical
Interfaces and port channels can be members of VLANs.
NOTE:
You can assign a static IP address to default VLAN 1 using the ip address command. To assign a different VLAN
ID to the default VLAN, use the default vlan-id vlan-id command.
Following table lists out the VLAN defaults in Dell Networking OS:
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Interfaces