What is an SVI in Networking? Difference Between SVI and VLAN

What is SVI in networking and the difference between SVI and VLAN? We will discuss these topics in detail in this article including how to configure SVI in a switch.

What is an SVI in Networking?  

SVI stands for Switched Virtual Interface, and it is a logical interface configured on a layer 3 switch that connects a VLAN to the routing engine of the switch. SVI allows traffic to be routed between VLANs by providing a default gateway for each VLAN. SVI also provides layer 3 IP connectivity to the switch and supports bridging and routing protocols.

SVI is different from a physical interface on a router, which creates a separate network segment and broadcast domain for each interface. With SVI, multiple VLANs can share the same physical interface on the switch, but each VLAN has its own logical interface and broadcast domain.

To create an SVI, you need to first create a layer 2 VLAN on the switch, and then assign an IP address to the corresponding layer 3 interface (SVI). For example, if you have VLAN 10 and VLAN 20 on the switch, you can create SVI 10 and SVI 20 with different IP addresses, and enable routing between them. You can also assign an IP address to the default SVI (VLAN 1) for remote management of the switch.

Some of the advantages of using SVI are:

• Faster and more efficient than router-on-a-stick, because the switching and routing are done in hardware.
• No need for external links or devices for inter-VLAN routing.
• Supports EtherChannel for increased bandwidth and redundancy between switches.
• Lower latency and higher performance than using a router.

 

What is the Difference Between SVI and VLAN? 

A VLAN is a logical network segment that groups devices on the same Layer 2 domain. A VLAN creates a separate broadcast domain and can improve network performance, security, and management. A VLAN is identified by a number between 1 and 4094.

An SVI is a logical interface on a Layer 3 switch that connects to a VLAN and provides Layer 3 processing of packets. An SVI has an IP address and mask and can act as a default gateway for devices on the same VLAN. An SVI also enables inter-VLAN routing and IP connectivity to the switch.

The main difference between SVI and VLAN is that an SVI is a virtual interface that provides Layer 3 functionality for a VLAN, while a VLAN is a logical network segment that provides Layer 2 functionality for devices. An SVI is bound to a VLAN used for Layer 2 switching, while a sub-interface is part of a Layer 3 interface that does not take part in Layer 2 switching. Only one SVI can be mapped to each VLAN. An SVI is virtual and has no physical port defined, while a VLAN can span multiple physical ports on one or more switches.

 

How Can I Configure SVI on a Switch? 

It might appear a bit difficult to nonprogrammer people at first sight when it comes to configuring SVI on a switch. To configure an SVI on a switch, you need to follow the steps that are demonstrated below:

• First, you need to create a VLAN on the switch using the VLAN command in global configuration mode. For example, to create VLAN 10, you can use the following command:

Switch(config)# vlan 10

• Next, you need to assign an IP address to the SVI using the interface VLAN command in global configuration mode. For example, to assign IP address 192.168.10.1/24 to VLAN 10, you can use the following command:

Switch(config)# interface vlan 10

Switch(config-if)# ip address 192.168.10.1 255.255.255.0

• Then, you need to enable the SVI using the no shutdown command in interface configuration mode. For example, to enable VLAN 10, you can use the following command:

Switch(config-if)# no shutdown

• Finally, you need to assign ports to the VLAN using the switchport access VLAN command in interface configuration mode. For example, to assign port 1 to VLAN 10, you can use the following command:

Switch(config)# interface fastEthernet 0/1

Switch(config-if)# switchport mode access

Switch(config-if)# switchport access vlan 10

 

Wrap Up 

We have discussed what is an SVI in networking and the differences between SVI and VLAN. And if you wanted to learn how to configure SVI on a switch, we got you covered on that as well. Hope you have learned some helpful information from this article.