Riverstone Networks RS 2100 - Manual (Page 25)

Riverstone Networks RS 2100 Switch Router Getting Started Guide 2-3
RS 2100 Introduction Software Overview
2.3 SOFTWARE OVERVIEW
This section describes the features and capabilities of the RS 2100 in greater detail. For full information regarding the
use of these features and capabilities, see the Riverstone RS Switch Router User Guide.
2.3.1 Bridging
The RS 2100 provides the following types of wire-speed bridging:
Address-based bridging – The RS 2100 performs this type of bridging by looking up a packet’s destination address
in an L2 lookup table on the line card that received the packet from the network. The L2 lookup table indicates the exit
port(s) for the bridged packet. If the packet is addressed to the RS 2100’s own MAC address, the packet is routed rather
than bridged.
Flow-based bridging – The RS 2100 performs this type of bridging by looking up a packet’s source and destination
address in an L2 lookup table on the line card that received the packet from the network.
Your choice of bridging method does not affect RS 2100 performance. However, address-based bridging requires
fewer table entries. Alternately, while flow-based bridging uses more table entries, it provides tighter management and
control over bridged traffic, and greater resolution to RMON I statistics.
The RS 2100 ports perform address-based bridging by default, but can be configured to perform flow-based bridging
on a per-port basis. A port cannot be configured to perform both types of bridging at the same time.
2.3.2 Port and Protocol VLANs
The RS 2100 supports the following types of Virtual LANs (VLANs):
Port-based VLANs – A port-based VLAN is a set of ports that comprises a layer-2 broadcast domain. The RS 2100
confines MAC-layer broadcasts to the ports in the VLAN on which the broadcast originates. RS 2100 ports outside the
VLAN do not receive the broadcast.
Protocol-based VLANs – A protocol-based VLAN is a named set of ports that comprises an IP, IPX, AppleTalk,
DECNet, SNA, IPv6, or L2 broadcast domain. The RS 2100 confines protocol-specific broadcasts to the ports within
the protocol-based VLAN. Protocol-based VLANs sometimes are called subnet VLANs or layer-3 VLANs.
You can include the same port in more than one VLAN, even in both port-based and protocol-based VLANs.
Moreover, you can define VLANs that span across multiple RS 2100 switches. To simplify VLAN administration, the
RS 2100 supports 802.1Q trunk ports, which allow you to use a single port to “trunk” traffic from multiple VLANs to
another RS 2100 or to a switch that supports 802.1Q.
2.3.3 Routing
The RS 2100 provides wire-speed routing for the following protocols:
IP – protocol that switching and routing devices use for moving traffic within the Internet and within many corporate
intranets
IPX – protocol by Novell used in NetWare products