Nortel 450-24t 用户指南

Using the BayStack 450 10/100/1000 Series Switch

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Your BayStack 450 switch supports two types of VLANs:

•

Port-based VLANs

A port-based VLAN is a VLAN in which the ports are explicitly configured to 
be in the VLAN. When you create a port-based VLAN, you assign a Port 
VLAN Identifier (PVID) and specify which ports belong to the VLAN. The 
PVID is used to coordinate VLANs across multiple switches.

•

Protocol-based VLANs

A protocol-based VLAN is a VLAN in which you assign your switch ports as 
members of a broadcast domain, based on the protocol information within the 
packet. Protocol-based VLANs can localize broadcast traffic and assure that 
only the protocol-based VLAN ports are flooded with the specified protocol 
type packets. Your switch ports can be members of multiple protocol-based 
VLANs that are not based on the same protocol. Only tagged ports can be 
members of multiple protocol-based VLANs that are based on the same 
protocol.

You can create port-based VLANs and protocol-based VLANs, in any 
combination, as long as you do not exceed a total of 64 VLANs.

Your BayStack 450 switch supports up to 64 VLANs with 802.1Q tagging 
available per port. Ports are grouped into broadcast domains by assigning them to 
the same VLAN. Frames received in one VLAN can only be forwarded within 
that VLAN, and IP multicast frames and unknown unicast frames are flooded only 
to ports in the same VLAN.

Setting up virtual LANs (VLANs) is a way to segment networks to increase 
network capacity and performance without changing the physical network 
topology (Figure 1-22). With network segmentation, each switch port connects to 
a segment that is a single broadcast domain. When a switch port is configured to 
be a member of a VLAN, it is added to a group of ports (workgroup) that belong 
to one broadcast domain.