- 270 -
F
IGURE
C-1 VLAN S
AMPLE
A
PPLICATION
C.3 Connecting VLAN Groups
The Switch supports communication within a common VLAN using store-and-forward switching.
However, if you have devices in separate VLANs that must communicate, and it is not practical to
include these devices in a common VLAN, then the VLANs can be connected via Layer 3 routing
provided by this switch.
Traditional routers use only physical port numbers in their routing tables, which provides no support for
VLANs. By contrast, this device supports Layer 3 routing by using both logical and physical port
numbers to support VLANs and Layer 3 switching simultaneously.
By using the abstraction of a logical port number to represent a collection of physical switch ports in the
same VLAN, Layer 3 switching can occur from one VLAN to another transparently without changing the
routing protocol and IP routing software, while Layer 2 switching is still used for intra-VLAN traffic.
The Switch uses standard routing tables that are constructed via static configuration or dynamic routing
protocols such as RIP. Each routing entry consists of a network address (that is, an IP address with a
subnet mask), and a virtual interface number. Each virtual interface corresponds to a virtual LAN,
