APPLICATION EXAMPLES

Making VLAN Connections

These switches support VLANs which can be used to organize any group of network nodes into separate broadcast domains. VLANs confine broadcast traffic to the originating group, and can eliminate broadcast storms in large networks. This provides a more secure and cleaner network environment.

VLANs can be based on untagged port groups, or traffic can be explicitly tagged to identify the VLAN group to which it belongs. Untagged VLANs can be used for small networks attached to a single switch. However, tagged VLANs should be used for larger networks, and all the VLANs assigned to the inter-switch links.

These switches also support multiple spanning trees which allow VLAN groups to maintain a more stable path between all VLAN members. This can reduce the overall amount of protocol traffic crossing the network, and provide a shorter reconfiguration time if any link in the spanning tree fails.

R&D

VLAN 1

Tagged

Ports

Finance

VLAN 2

Testing

VLAN 3

VLAN 4

Untagged Ports

Tagged Port

VLAN

unaware

switch

Marketing

Finance

VLAN 3

VLAN aware switch

R&D

Testing

VLAN 1

VLAN 2

Figure 2-4 Making VLAN Connections

Note: When connecting to a switch that does not support IEEE 802.1Q VLAN tags, use untagged ports.

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SMC Networks SMC7824M/ESW manual Making Vlan Connections