Configuring Basic Settings Of A Vlan Interface - 3Com 4500G Family Configuration Manual

As the default VLAN, VLAN 1 cannot be created or removed.
You cannot manually create or remove VLANs reserved for special purposes.
Dynamic VLANs cannot be removed with the undo vlan command.
A VLAN with a QoS policy applied cannot be removed.
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.
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...
Enter system view
Create a VLAN
interface and enter
VLAN interface view
Assign an IP address
to the VLAN interface
Configure the
description of the
VLAN interface
Bring up the VLAN
interface
Use the command...
system-view
interface vlan-interface
vlan-interface-id
ip address ip-address
{ mask | mask-length }
[ sub ]
description text
undo shutdown
1-4
Remarks
—
Required
If the VLAN interface already exists, you enter
its view directly.
Optional
No IP address is assigned to any VLAN
interface by default.
Optional
VLAN interface name is used by default, for
example, Vlan-interface1 Interface.
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.