4-1
v1.0, June 2010
Chapter
4
VLAN Routing
In this chapter, the following examples are provided:
•
“Create Two VLANs”
•
“Set Up VLAN Routing for the VLANs and the Switch” on page
4-6
•
“Click Add to save the settings.” on page
4-8
You can configure the 7000 Series Managed Switch with some ports supporting VLANs and some
supporting routing. You can also configure it to allow traffic on a VLAN to be treated as if the VLAN were
a router port.
When a port is enabled for bridging (the default) rather than routing, all normal bridge processing is
performed for an inbound packet, which is then associated with a VLAN. Its MAC Destination Address
(DA) and VLAN ID are used to search the MAC address table. If routing is enabled for the VLAN and the
MAC DA of an inbound unicast packet is that of the internal bridge-router interface, the packet will be
routed. An inbound multicast packet will be forwarded to all ports in the VLAN, plus the internal bridge-
router interface if it was received on a routed VLAN.
Since a port can be configured to belong to more than one VLAN, VLAN routing might be enabled for all of
the VLANs on the port, or for a subset. VLAN Routing can be used to allow more than one physical port to
reside on the same subnet. It could also be used when a VLAN spans multiple physical networks, or when
additional segmentation or security is required.
The next section will show you how to configure the 7000 Series Managed Switch to support VLAN routing
and how to use RIP and OSPF. A port may be either a VLAN port or a router port, but not both. However, a
VLAN port may be part of a VLAN that is itself a router port.
Create Two VLANs
This section provides an example of how to configure the 7000 Series Managed Switch to support VLAN
routing. The configuration of the VLAN router port is similar to that of a physical port. The main difference
is that, after the VLAN has been created, you must use the
show ip vlan
command to determine the VLAN’s
interface ID so that you can use it in the router configuration commands.
