Chapter 13: Virtual LANs
162
does not match one of the Group IDs assigned to the port, the packet is
discarded.
Port VLAN Identifier (PVID)
When an untagged packet is received on a port in a tagged VLAN, it is
assigned to one of the VLANs of which that port is a member. The
deciding factor in this process is the Port VLAN Identifier (PVID). Both
tagged and untagged ports in a tagged VLAN must have a PVID assigned
to them. The default value of the PVID for each port is 1. The switch
associates a received untagged packet to the VLAN ID that matches the
PVID assigned to the port, and the packet is only forwarded to those ports
that are members.
General Rules for Creating a Tagged VLAN
Here is a summary of the rules to observe when you create a tagged
VLAN:
Assign a unique name to each tagged VLAN.
Each tagged VLAN must be assigned a unique VLAN
ID. If a particular VLAN spans multiple switches, each
part of the VLAN on the different switches must be
assigned the same VLAN ID.
A tagged port can be a member of multiple VLANs.
The AT-GS950/48 Gigabit Ethernet Switch can support
up to 255 tagged VLANs per switch.
Private VLAN
Overview
Private VLANs create special broadcast domains in which the traffic of the
member ports is restricted to source ports. Ports in a private port VLAN
are only allowed to forward traffic to, and receive traffic from, a designated
source port, and are prohibited from forwarding traffic to each other.
An example application of a private port VLAN would be a library in which
user booths each have a computer with Internet access. In this situation, it
would usually be undesirable to allow communication between these
individual PCs. Connecting the computers to ports within a private isolated
VLAN would enable each computer to access the Internet or a library
server via a single connection, while preventing access between the
computers in the booths.
Another application for private port VLANs is to simplify IP address
assignments. Ports can be isolated from each other while still belonging to
the same subnet.
A private port VLAN consists of one or more forwarding ports and a source
port.
Summary of Contents for AT-GS950/48
Page 10: ...Contents 10...
Page 14: ...Figures 14...
Page 16: ...List of Tables 16...
Page 20: ...Preface 20...
Page 22: ...22...
Page 62: ...Chapter 2 System Configuration 62...
Page 64: ...64...
Page 108: ...Chapter 6 Static Port Trunking 108...
Page 124: ...Chapter 8 Port Mirroring 124...
Page 186: ...Chapter 13 Virtual LANs 186...
Page 194: ...Chapter 14 GVRP 194...
Page 210: ...210...
Page 224: ...Chapter 16 SNMPv1 and v2c 224...
Page 242: ...Chapter 17 SNMPv3 242...
Page 258: ...Chapter 18 Access Control Configuration 258...
Page 272: ...Chapter 19 RMON 272...
Page 302: ...Chapter 21 Security 302...
Page 324: ...Chapter 23 LLDP 324...
Page 338: ...338...
Page 356: ...Chapter 27 LED ECO Mode 356...
Page 360: ...Chapter 28 Energy Efficient Ethernet 360...
Page 370: ...Chapter 29 Rebooting the AT GS950 48 370...
Page 392: ...Appendix A MSTP Overview 392...