Multilayer Switching

Final Project Lab

The function and configuration Multilayer switching.

Multilayer switching is the combination of traditional Layer 2 switching with Layer 3 routing in a single product. Multilayer switching is new, and there is no industry standard.. The term multilayer switch seems to be the best and most widely used description of this class of product that performs both Layer 3 routing and Layer 2 switching functions. Multilayer Switch Multilayer switches support both Layer-2 (switching) and Layer-3 (routing) functions. Three port types can exist on Multilayer switches:

1. Switchports – Layer-2 ports on which MAC addresses are learned. 2. Layer-3 Ports – Essentially routing ports on multi-layer switches. 3. Switched Virtual Interfaces (SVI) – A VLAN virtual interface

By default, on Catalyst 2950’s and 3550’s, all interfaces are switchports. To configure a port as a switchport: Switch(config)# interface fa# Switch(config-if)# switchport

To configure a port as a Layer-3 (routing) port, and assign an IP address: Switch(config)# interface fa# Switch(config-if)# no switchport Switch(config-if)# ip address #.#.#.# #.#.#.# Switch(config-if)# no shut

To assign an IP address to an SVI (virtual VLAN interface): Switch(config)# interface vlan # Switch(config-if)# ip address #.#.#.# #.#.#.# Switch(config-if)# no shut Note that the VLAN itself is treated as an interface, and supports most IOS interface commands. To view the port type of a particular interface:

Switch# show int fa# switchport Name: Fa# Switchport: Enabled A Layer-3 interface would display the following output: Switch# show int fa# switchport Name: Fa# Switchport: Disabled

Configuration of inter-VLAN routing on a multilayer switch

. create the required VLANs: Switch(config)# vlan # Switch(config-vlan)# name VLAN# Switch(config)# vlan # Switch(config-vlan)# name VLAN#

Then, routing must be globally enabled on the multilayer switch: Switch(config)# ip routing

Next, each VLAN SVI is assigned an IP address: Switch(config)# interface vlan # Switch(config-if)# #.#.#.# #.#.#.# Switch(config-if)# no shut Switch(config)# interface vlan # Switch(config-if)# #.#.#.# #.#.#.# Switch(config-if)# no shut