3Com 4007, Implementation Manual, Page: 286 / 684

286 C
HAPTER
14: V
IRTUAL
LAN
S
(VLAN
S
)
Example 2: One-Armed Routing Configuration
Figure 20 shows a one-armed router configuration. (The switch fabric
module resides in slot 7 but is logically represented above the other
modules.)
In this configuration:
■
There are three Layer 2 modules, a Multilayer Switching Module, and
the switch fabric module.
■
There are four VLANs:
■
VLAN1, the default VLAN on all modules (tagged on the
front-panel and backplane ports of the Layer 2 modules and on the
corresponding switch fabric module ports). The default VLAN is not
represented in the figure.
■
VLAN2, a port-based VLAN that is defined on the Layer 2 modules
in slot 1 and slot 2. It is defined as a protocol-based VLAN for IP on
the Multilayer Switching Module in slot 4. The IP routing interface
for IP VLAN 2 (150.10.2.12) is defined to be on the same
subnetwork as the devices connected to the Layer 2 modules in
slots 1 and 2. (For example, a PC is defined as 150.10.2.1.)
■
VLAN3, a port-based VLAN that is defined on the Layer 2 module
in slot 2. It is defined as a protocol-based VLAN for IP on the
Layer 3 module in slot 4. The IP routing interface for IP VLAN 3
(150.10.3.12) is defined to be on the same subnetwork as the
devices that are connected to the Layer 2 module in slot 2.
■
VLAN4, a port-based VLAN that is defined on the Layer 2 module
in slot 3. It is defined as a protocol-based VLAN for IP on the
Layer 3 module in slot 4. The IP routing interface for IP VLAN 4
(150.10.4.12) is defined to be on the same subnetwork as the
devices that are connected to the Layer 2 module in slot 3.
■
On the Multilayer Switching Module, the backplane port 13 is part of
all four VLANs and is tagged in all four. IP routing is enabled with RIP.