Introduction To Vlans; Vlan Ids; Pvid - HP nj2000 User Manual

Introduction to VLANs

VLANs (or Virtual LANs) are logical partitions of the physical LAN. You can use VLANs to:
Increase network performance
Increase internal network security
Create separate broadcast domains
If the network has adequate performance and security for your current needs, it is recommended that you leave the
VLAN settings in the default configuration. The default configuration is as follows:
All ports are members of VLAN 1
The switch management interface is on VLAN 1 (this cannot be changed)
All ports have a Port VLAN ID (PVID) of 1
All ports can send and receive both VLAN-tagged and untagged packets (i.e. they are "hybrid" ports)
In the default configuration, any port is able to send traffic to any other port and a PC connected to any port will be
able to reach the management interface. Broadcast traffic, for example, will be flooded to all ports on the switch.
There are three different parameters that can be configured for each port on the switch; VLAN IDs (VLAN
membership), PVID and Packet Type. Note that the ports within a Trunk cannot be configured individually;
configure the Trunk instead (Trunks are labeled T1 to T4).

VLAN IDs

VLAN 1 is a special VLAN; it cannot be deleted and, if there is a possibility that a port could become
isolated, the Web User-interface will add the port to VLAN 1.
You can add up to 64 VLANs to the configuration of the switch. Each VLAN must be given a VLAN ID in
the range 1-4094.
A port can be a member of up to 64 VLANs.
All packets travelling through the switch are associated with one and only one VLAN.
If a port is not a member of a VLAN, it cannot send or receive packets associated with that VLAN.
A tagged packet carries its VLAN ID in the payload of the packet.
An untagged packet, received on a port with
identified by the PVID.

PVID

The PVID is (Port VLAN ID) is the VLAN ID that is associated with untagged, ingress packets.
It is not possible to remove a port from VLAN 1 unless its PVID has been changed to something other
than 1.
Outgoing packets are tagged unless the packet's VLAN ID is the same as the PVID. When the PVID is set
to "None," all outgoing packets are tagged.
Copyright © 2009 3Com Corporation. All Rights Reserved.
3Com Network Jack NJ2000
Packet Type set to All, is associated with the VLAN
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