Riverstone Networks WICT1-12 - Manual (Page 68)

5-4 Riverstone Networks RS Switch Router User Guide Release 8.0
VLAN Overview Bridging Configuration Guide
Most commonly, an RS is used as a combined switch and router. For example, it may be connected to two subnets S1
and S2. Ports 1-8 belong to S1 and ports 9-16 belong to S2. The required behavior of the RS is that intra-subnet frames
be bridged and inter-subnet packets be routed. In other words, traffic between two workstations that belong to the same
subnet should be bridged, and traffic between two workstations that belong to different subnets should be routed.
The RS switching routers use VLANs to achieve this behavior. This means that a L3 subnet (i.e., an IP or IPX subnet)
is mapped to a VLAN. A given subnet maps to exactly one and only one VLAN. With this definition, the terms VLAN
and subnet are almost interchangeable.
To configure an RS as a combined switch and router, the administrator must create VLANs whenever multiple ports
of the RS are to belong to a particular VLAN/subnet. Then the VLAN must be bound to an L3 (IP/IPX) interface so
that the RS knows which VLAN maps to which IP/IPX subnet.
Ports, VLANs, and L3 Interfaces
The term port refers to a physical connector on the RS, such as an ethernet port. Each port must belong to at least one
VLAN. When the RS is unconfigured, each port belongs to a VLAN called the “default VLAN.” By creating VLANs
and adding ports to the created VLANs, the ports are moved from the default VLAN to the newly created VLANs.
Unlike traditional routers, the RS has the concept of logical interfaces rather than physical interfaces. An L3 interface
is a logical entity created by the administrator. It can contain more than one physical port. When an L3 interface
contains exactly one physical port, it is equivalent to an interface on a traditional router. When an L3 interface contains
several ports, it is equivalent to an interface of a traditional router which is connected to a layer-2 device such as a
switch or bridge.
5.3.2 Configuration Examples
VLANs are used to associate physical ports on the RS with connected hosts that may be physically separated but need
to participate in the same broadcast domain. To associate ports to a VLAN, you must first create a VLAN and then
assign ports to the VLAN. This section shows examples of creating an IP or IPX VLAN and a DECnet, SNA, and
AppleTalk VLAN.
Creating an IP or IPX VLAN
In this example, servers connected to port gi.1.(1-2) on the RS need to communicate with clients connected to
et.4.(1-8). You can associate all the ports containing the clients and servers to an IP VLAN called ‘BLUE’.
First, create an IP VLAN named ‘BLUE’
Next, assign ports to the ‘BLUE’ VLAN.
rs(config)# vlan create BLUE ip
rs(config)# vlan add ports et.4.(1-8),gi.1.(1-2) to BLUE