Dell PowerConnect B-FCXs Configuration Manual page 501

Example
Suppose you want to move routing out to each of three buildings in a network. Remember that the
only protocols present on VLAN 2 and VLAN 3 are IP and IPX. Therefore, you can eliminate tagged
ports 25 and 26 from both VLAN 2 and VLAN 3 and create new tagged port-based VLANs to
support separate IP subnets and IPX networks for each backbone link.
You also need to create unique IP subnets and IPX networks within VLAN 2 and VLAN 3 at each
building. This will create a fully routed IP and IPX backbone for VLAN 2 and VLAN 3. However, VLAN
4 has no protocol restrictions across the backbone. In fact there are requirements for NetBIOS and
DecNet to be bridged among the three building locations. The IP subnet and IPX network that exists
within VLAN 4 must remain a flat Layer 2 switched STP domain. You enable routing for IP and IPX
on a virtual routing interface only on device-A. This will provide the flat IP and IPX segment with
connectivity to the rest of the network. Within VLAN 4 IP and IPX will follow the STP topology. All
other IP subnets and IPX networks will be fully routed and have use of all paths at all times during
normal operation.
Figure 98
FIGURE 98
Building 1
Device-A Device-A
Vlan2 Vlan8 Vlan3
To configure the Layer 3 VLANs and virtual routing interfaces on the Layer 3 Switch in
use the following procedure.
Configuring device-A
Enter the following commands to configure device-A. The following commands enable OSPF or RIP
routing.
PowerConnect B-Series FCX Configuration Guide
53-1002266-01
Routing between VLANs using virtual routing interfaces (Layer 3 Switches only)
shows the configuration described above.
Routing between protocol-based VLANs
/IPX V5
V4
Vlan4
Device-C
V6
IP
Vlan2 Vlan8
Building 3
IP/IPX V4 V5 IP/IPX
Device-C
V4
Vlan3
Vlan4
Building 2
Device-B Device-B
Vlan2 Vlan8 Vlan3 Vlan4
= STP Blocked VLAN
Figure
13
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