What are the four steps to configure inter-VLAN routing on a Layer 3 switch?

Create VLANs (Virtual Local Area Networks), create SVI (Switch Virtual Interface) interfaces with IP (Internet Protocol) addresses, configure access ports, and enable IP routing with the ip routing command.

Step 1 — Create VLANs:

D1(config)# vlan 10
D1(config-vlan)# name LAN10
D1(config)# vlan 20
D1(config-vlan)# name LAN20

Step 2 — Create SVI interfaces (these become the default gateways):

D1(config)# interface vlan 10
D1(config-if)# description Default Gateway for VLAN 10
D1(config-if)# ip address 192.168.10.1 255.255.255.0
D1(config-if)# no shut

D1(config)# interface vlan 20
D1(config-if)# description Default Gateway for VLAN 20
D1(config-if)# ip address 192.168.20.1 255.255.255.0
D1(config-if)# no shut

Step 3 — Configure access ports:

D1(config)# interface G1/0/6
D1(config-if)# switchport mode access
D1(config-if)# switchport access vlan 10

Step 4 — Enable IP routing:

D1(config)# ip routing

This last step is critical and easy to forget — without ip routing, the Layer 3 switch won't actually route between VLANs even though the SVIs are configured.

Go deeper:

• Inter-VLAN Routing using Layer 3 Switches (Cisco Press) — create VLANs, configure SVIs as gateways, assign access ports, enable ip routing.
• Layer 3 Switch InterVLAN Routing (Study-CCNA) — step-by-step with multiple SVIs and show ip route verification.