Ssr Vlan Support - Cabletron Systems SmartSwitch 8-slot User's Reference Manual

configured by the network administrator. When a frame is received at a port, its
destination MAC address is looked up in the VLAN database, which returns the VLAN
to which this frame belongs.
This type of VLAN is powerful in the sense that network devices such as printers and
workstations can be moved anywhere in the network without the need for network
reconfiguration. However, the administration is intensive because all MAC addresses
on the network need to be known and configured.
Protocol-based VLANs
Protocol-based VLANs divide the physical network into logical VLANs based on
protocol. When a frame is received at a port, its VLAN is determined by the protocol
of the packet. For example, there could be separate VLANs for IP, IPX and Appletalk.
An IP broadcast frame will only be sent to all ports in the IP VLAN.
Subnet-based VLANs
Subnet-based VLANs are a subset of protocol based VLANs and determine the VLAN
of a frame based on the subnet to which the frame belongs. To do this, the switch must
look into the network layer header of the incoming frame. This type of VLAN behaves
similar to a router by segregating different subnets into different broadcast domains.
Multicast-based VLANs
Multicast-based VLANs are created dynamically for multicast groups. Typically, each
multicast group corresponds to a different VLAN. This ensures that multicast frames
are received only by those ports that are connected to members of the appropriate
multicast group.
Policy-based VLANs
Policy-based VLANs are the most general definition of VLANs. Each incoming
(untagged) frame is looked up in a policy database, which determines the VLAN to
which the frame belongs. For example, you could set up a policy which creates a
special VLAN for all email traffic between the management officers of a company, so
that this traffic will not be seen anywhere else.

SSR VLAN Support

The SSR supports:
• Port-based VLANs
• Protocol-based VLANs
• Subnet-based VLANs
When using the SSR as an L2 bridge/switch, use the port-based and protocol-based
VLAN types. When using the SSR as a combined switch and router, use the subnet-
based VLANs in addition to port-based and protocol-based VLANs. It is not necessary
SSR User Reference Manual
Chapter 2: Bridging Configuration Guide
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