Vlan Configuration; Figure 25. Switch With Four Vlans - Cabletron Systems SmartSTACK STS16-20RM Installation And User Manual

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VLAN Configuration

The Virtual LAN feature can be used to partition a switch or a stack of switches into
several Virtual LANs, each containing its own set of ports (the terms Virtual LAN
and domain are interchangeable). Packets are forwarded only between ports
belonging to the same VLAN. The benefit of Virtual LAN is to restrict access from
one segment to another, either for security purposes or to reduce intersegment
traffic. Figure 25 illustrates a switch with four VLANs.

Figure 25. Switch with Four VLANs

To set up domains using the VLAN Configuration menu, specify the ports
belonging to the domains, then set up the IP configurations, trap configuration (trap
receivers are associated with a set of VLANs and a receiver IP address) and STP
configurations specific to the appropriate VLANs. If you have already supplied
configuration information using the main configuration menus, that information
applies to VLAN "default". Virtual LANs affects other switch features in the
following ways:
•
Spanning tree protocol (STP). If you are using STP in a certain domain, you
must supply STP information for that domain. The STP software treats ports
on other domains as nonexistent. Domains do not affect port priorities and port
costs. You set these parameters using the STP Configuration menu that you
select from the main Configuration menu. Note that all BRFs defined in a
switch use the same STP bridge identifier. This means that BRFs from the
same switch or stack of switches cannot participate in the same spanning tree.
In other words, the spanning tree protocol will not work properly if VLANs are
connected.
•
SNMP trap tables. Each domain appears to the network management system
as a physically different Token Ring switch unit. Certain MIB II objects and
proprietary objects are domain-sensitive, while others are not. For a list of
domain-sensitive objects, see Chapter 7, "Monitoring the Network from the
Console Statistics Menu".
SmartStack STS16-20RM/STS16-20FRM Token Ring Switches, P/N: 9032957-01 Switch Configuration