1-4
z
As the default VLAN, VLAN 1 cannot be created or removed.
z
You cannot manually create or remove VLANs reserved for special purposes.
z
Dynamic VLANs cannot be removed with the
undo vlan
command.
z
A VLAN with a QoS policy applied cannot be removed.
z
For isolate-user-VLANs or secondary VLANs, if you have used the
isolate-user-vlan
command to
create mappings between them, you cannot remove them until you remove the mappings between
them first.
z
A VLAN operating as a probe VLAN for remote port mirroring cannot be removed with the undo
vlan command. To do that, remove the remote mirroring VLAN configuration from it first.
Configuring Basic Settings of a VLAN Interface
For hosts of different VLANs to communicate, you must use a router or Layer 3 switch to perform layer
3 forwarding. To achieve this, VLAN interfaces are used.
VLAN interfaces are virtual interfaces used for Layer 3 communication between different VLANs. They
do not exist as physical entities on devices. For each VLAN, you can create one VLAN interface. You
can assign the VLAN interface an IP address and specify it as the gateway of the VLAN to forward traffic
destined for an IP network segment different from that of the VLAN.
Follow these steps to configure basic settings of a VLAN interface:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Create a VLAN
interface and enter
VLAN interface view
interface vlan-interface
vlan-interface-id
Required
If the VLAN interface already exists, you
enter its view directly.
Assign an IP address
to the VLAN interface
ip
address
ip-address
{
mask
|
mask-length
} [
sub
]
Optional
No IP address is assigned to any VLAN
interface by default.
Configure the
description of the
VLAN interface
description text
Optional
VLAN interface name is used by default, for
example,
Vlan-interface1 Interface.
Bring up the VLAN
interface
undo shutdown
Optional
By default, a VLAN interface is in the up
state. In this case, the VLAN interface is up
so long as one port in the VLAN is up and
goes down if all ports in the VLAN go down.
An administratively shut down VLAN
interface however will be in the down state
until you bring it up, regardless of how the
state of the ports in the VLAN changes.
