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CONFIGURING VLANS

 

VLANs are logical subgroups with a Local Area Network (LAN) which combine user stations and network devices into a single unit, regardless of the physical LAN segment to which they are attached. VLANs allow network traffic to flow more efficiently within subgroups. VLANs use software to reduce the amount of time it takes for network changes, additions, and moves to be implemented. VLANs restrict traffic within the VLAN.

VLANs have no minimum number of ports, and can be created per unit, per device, or through any other logical connection combination, since they are software-based and not defined by physical attributes.

VLANs function at Layer 2. Since VLANs isolate traffic within the VLAN, a Layer 3 router is required to allow traffic flow between VLANs. Layer 3 routers identify segments and coordinate with VLANs. VLANs are Broadcast and Multicast domains. Broadcast and Multicast traffic is transmitted only in the VLAN in which the traffic is generated.

VLAN tagging provides a method of transferring VLAN information between VLAN groups. VLAN 1is the default VLAN. All ports are members of VLAN 1 by default. If the untagged port is moved to a new VLAN, the port is removed from VLAN 1. For example: If an untagged port 24 is moved to VLAN 5, the port will no longer be a member of VLAN 1. However, if the port is added to VLAN 5 as a tagged port it then remains untagged in VLAN 1.

This section contains the following topics:

Viewing VLAN Details

Viewing VLAN Port Details

Creating VLANs

Renaming VLANs

Modifying VLAN Settings

Modifying Port VLAN Settings

Removing VLANs

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3Com 3CRDSF9PWR manual Configuring Vlans