Cabletron Systems SSR-ATM29-02, Руководство пользователя, Страница: 81 / 386

CoreWatch User’s Guide 81
Chapter 7
Configuring VLANs
on the SSR
You configure VLANs to limit the scope of traffic on the SSR. This chapter
• provides an overview of VLANs on the SSR.
• lists tips that make VLAN configuration easy.
• discusses defining ports for VLANs.
• discusses creating the different VLANs the SSR supports.
• describes copying ports to add them to a VLAN.
• discusses modifying VLANs.
A Look at VLANs on the SSR
VLANs contain Layer-2 broadcast and multicast traffic. No traffic is allowed to cross
VLAN boundaries unless it passes through routers. Once connected by routers, VLANs
are equivalent to subnets.
VLANs are created by grouping a set of bridged ports together as part of one bridged
network. Broadcasts from one of the ports in a VLAN are received by other ports in the
group but not by any ports outside of the group. Similarly, unicast traffic is bridged only
between ports in a group but not to ports outside of the group. Thus, traffic is not allowed
to cross the group boundary. A bridge may have multiple VLANs defined thus appearing
as multiple virtual bridges on the SSR.
The SSR supports the following types of VLANs. The VLAN type determines the type of
traffic the SSR will forward on the VLAN.