O - ODR, P - periodic downloaded static route Ia - IS-IS inter area, * - candidate default, U - per-user static route, I - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2, N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2Į1 - OSPF external type 1, E2 - OSPF external type 2, show ip route – provides a snapshot of the routing table entries.Ĭodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGPĭ - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area.We can use the following show commands to confirm that our Layer 3 Switch interVLAN configuration runs properly: Step 6: Configure the default route for the switch. In its place, configure an IP address for that VLAN interface. This step can be disregarded if the switch reaches the default router through a VLAN. The IP address allocated is within the same subnet as the default router. The ‘ no switchport’ command allows the physical ports to attain Layer 3 routing functionality. Switch(config)#interface FastEthernet 0/1 In this case, it is FastEthernet 0/1 for the Cisco Catalyst 3550. Step 5: IP configuration facing the default router should look like the commands below. %LINK-5-CHANGED: Interface Vlan30, changed state to up %LINK-5-CHANGED: Interface Vlan20, changed state to up %LINK-5-CHANGED: Interface Vlan10, changed state to up Switch#configure terminalĮnter configuration commands, one per line. Step 4: Configure the IP address on the VLAN interfaces based on the network diagram above. This example shows the addition of VLANs 2, 3, and 10 to the switch VLAN database. If they do not exist, add the VLANs to the switch. Step 3: Use the ‘show vlan’ command to verify that the VLANs exist in the VLAN database.
Based on the network topology above, it is VLANs 10, VLAN 20, and VLAN 30. Step 2: Take note of the VLANs that must be routed. Even though this command is usually enabled, it does not hurt to be certain that it is. Step 1: Enable routing capability on the switch. In this simple Inter-VLAN routing scenario, we will be using a Cisco Catalyst 3550 as our Layer 3 Switch.
How to Configure Layer 3 Switch InterVLAN Routing?īelow is a diagram that we can use as a reference in understanding how to configure Inter-VLAN routing and test inter-switch connectivity across the network before configuring its routing capability. Layer 3 switches convert a Layer 2 switch interface to a Layer 3 interface, making it a routed port similar to a physical interface on a Cisco IOS router.
The latest Cisco Catalyst Switches are equipped with the Enhanced Multilayer Image (EMI), which can work as a Layer 3 device with full routing capabilities, also known as a multi-layer switch (MLS).