Installation guide

C HAPTER 2 | Network Planning
Application Examples
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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.
At Layer 3, VLANs are used to create an IP interface, where one or more ports
are assigned to the same IP segment. Traffic is automatically routed between
different IP segments on the same switch, without any need to configure routing
protocols.
Figure 10: Making VLAN Connections
N OTE : When connecting to a switch that does not support IEEE
802.1Q VLAN tags, use untagged ports.
Finance
Marketing
VLAN 3
Untagged Ports
VLAN
unaware
switch
Tagged Port
VLAN
aware
switch
Tagged
Ports
Finance
VLAN 3
R&D
VLAN 2
Testing
R&D
Testing
VLAN 1
VLAN 2
VLAN 4
VLAN 1