How Is Traffic Routed Between Multiple Vlans On A Multilayer Switch?

How is traffic routed between multiple VLANs on a multilayer switch?

• With the help of the physical interface, the traffic is routed.
• The traffic is routed through internal VLAN interfaces.
• Traffic is routed through the subinterface.
• The traffic is broadcast out of all physical interfaces.

Answer: The multilayer layer switches the inter-VLAN routing with the use of the internal VLAN interfaces. The outer physical interface may receive the traffic but they are not necessary for the routing function. During the routing of the VLANs, the traffic of the broadcast which is received on VLAN will remain on the ports which are the members of that VLAN. For the multiple VLANs on the multilayer switches the sub-interfaces are not suitable.

Multilayer switch

A layer 3 switch is called the multilayer switch a device that connects the switch with the router.it is the same as the traditional switches which have 24 or maybe 48 ports or some SFP-ready ports. The difference between both of them is inside the box in the hardware or software.

The switch has the ASICS which is used for the functionalities of layer 3. the switch has the dedicated hardware for it that’s why it is quicker than the router. The multilayer switch has various IP addresses and it also assists with the static routes and the dynamic routes.

Inter-VLAN routing for the multilayer switch

Along with the router on a stick, the switches sent the traffic to the router and the traffic move back toward the switches by performing the frame rewrite and routing. All the works happen in the layer 3 switches. The switch has the assistance of switch virtual interface (SVIs). which performs the routing.it can act as the physical interface because it has the IP address and also can inject the connected route to the routing table. But for each VLAN only one SVI is present. The routing starts with the switch when the packet is received by the switch in VLAN, which is for layer 2.

Since the SVIs are logical, the MAC address for it is present in the software and not in the hardware. The rewrite operations for the frames are performed in the multi-layer switch, it has the same features as the normal switch and is also connected with other switches which are multilayer.

Configuration of the multilayer switch

For the configuration, the first step is enabling the routing on the multilayer switch and by default, they work as the traditional in case you want to use as the layer 2 switch and for this, a command ip routing is written in the command prompt. But some of the devices have the configuration with multilayer switch by default.