Question About InterVLAN Routing

shimabukushimabuku Posts: 13Member ■□□□□□□□□□
By looking at the diagram in the link, Configuring InterVLAN Routing with Catalyst 3750/3560/3550 Series Switches - Cisco Systems

Would the router have subinterfaces on Fa0/0 for each VLAN? Or is the layer 3 switch taking care of it? Is it safe to say that the router is running some kind of routing protocol so traffic is able to reach the internet?


  • FrankGuthrieFrankGuthrie Posts: 245Member
    If you configure the Layer 3 switch, also called an Multi Layer Switch (MLS), with the #ip routing command, then routing between the VLAN's is done by the switch and you don't need sub-interfaces on the router, as the traffic is passed as Layer 3 to the Router.

    If you don't configure the Layer 3 Switch with the #ip routing command, which basically makes the switch a Layer 2 switch, you do need to create sub-interfaces on the Router.
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