An SVI (Switched Virtual Interface) is a virtual L3 interface inside a switch, associated with a VLAN. When the switch is enabled for IP routing, the SVI becomes the gateway for hosts in that VLAN - just like a router interface, but inside the switch and handled in hardware. This is the modern replacement for router-on-a-stick. This lab promotes the ioll2-xe SW1 to an L3 switch with SVIs and a "no switchport" routed port.
What you will learn
- The difference between an L2-only switch and an L3 (multilayer) switch
- How to enable IP routing globally on a switch
- How to create an SVI and assign an IP to a VLAN
- The "no switchport" command that turns an Ethernet port into a routed L3 port
- How the switch's routing table integrates SVIs and routed ports
What this lab does NOT cover
- Dynamic routing protocols on the L3 switch (covered in IP Connectivity pillar)
- VLAN-to-VLAN ACLs
- The hardware ASIC details that make L3 switching fast
Topology
Download the PingLabz CCNA Base Topology .yaml
The PingLabz CCNA Base Topology - three iol-xe routers + one alpine host + one ioll2-xe managed switch + one unmanaged switch. The reusable foundation.