As a network administrator, work may encompass having actually to segment a solitary switched Local Area Netoccupational (LAN) logically without having actually to run new cables and also changing the existing network-related. The concept of “VLAN” and its configurations will assist one handle the job at hand via ease.

You are watching: What is an advantage of using legacy inter-vlan routing?

In this write-up, we will certainly learn around what inter-VLAN routing is, various methods for VLAN routing, and also also develop a netjob-related configuration to understand how it works.

Table of contents

Inter-VLAN routing methodsNetwork-related configurations for Inter-VLAN communication making use of Router-On-Stick method


As a prerequisite, the reader have to have actually a good expertise of basic netfunctioning principles, and also just how to occupational with Cisco packet tracer.

To download and also install Cisco packet tracer on your computer, visit this link.

VLAN routing terminologies

VLAN is a network segment on a switched LAN which teams together the hosts on the network-related, logically, regardless of their physical places on the network-related.A Local Area Network (LAN) is a physical interconnection of network devices in a small geographical location.Layer 3 switch/multilayer switch is a unique type of switch which percreates the feature of both switches at layer 2 and also routers at layer 3 of the OSI version i.e., it have the right to forward both the frames and also packets.Switched Virtual Interchallenge (SVI) refers to a virtual interchallenge which connects VLANs on the network tools to their particular rexternal engines.Default Gatemeans is an equipment that forwards IP packets and also gives an accessibility suggest to the various other netfunctions. For instance, a rexternal.Access Point is a network tool that connects to a rexternal or switch, producing a wiremuch less local location netoccupational and also acting as a connect in between the rexternal and also the netoccupational customers.Switch port describes a physical opening on the switch or router wbelow ethernet cables can be plugged.Router Interchallenge describes a path that allows the rexternal to connect to the netjob-related.

What is Inter-VLAN routing?

Virtual LANs (VLANS) are networks segments on a switched LAN. Inter-VLAN routing describes the movement of packets across the network in between hosts in various network-related segments.

VLANs make it less complicated for one to segment a netoccupational, which in turn enhances the performance of the netjob-related and also makes it even more versatile, since they are logical connections.

VLANs act as sepaprice subnet on the network. To move packets from one VLAN to another and also permit communications among hosts, we need to connumber the VLAN netjob-related.

Inter-VLAN routing methods

Legacy inter-VLAN routing

In this technique, multiple router interencounters are supplied, each connecting to a switch port in different VLANs. These interencounters are served as default gatemeans, which requires extra cabling once the netjob-related hregarding be expanded.

Hence, including added netjob-related cables and also improving infrastructure is more expensive.


In this strategy, unprefer the tradition routing, one physical interchallenge port is supplied for routing the web traffic between the netjob-related segments. The netjob-related administrator doesn’t have to produce separate VLAN interfaces prefer fa0/1 to fa0/10.

Instead, all the interdeals with from 1 to 10 are developed through a solitary interconfront. This approach is easy to implement and also used for tiny to medium-sized netfunctions.

Layer 3 switch making use of Switched Virtual Interconfront (SVI)

Currently, this method of inter-VLAN routing that offers layer 3/multilayer switch and Switched Virtual Interencounters (SVI) is the a lot of desired.

SVIs are produced for VLANs exists on the switch which performs the very same attribute for the VLANs as that of a router.

Layer 3 switches are expensive, which are mostly suitable for big organization networks.

Netoccupational configurations for Inter-VLAN communication making use of Router-On-Stick method

In this post, we will learn just how to connumber inter-VLAN routing making use of the router-on-a-stick technique.

Consider a LAN through 4 PCs, 1 switch, and a rexternal connected as presented in the image:


Now, we have to configure 2 VLANs 10 and also 20, with PC0 and PC1 on VLAN10, and PC2 and also PC3 are on VLAN20.

IP Address of PC0 - Address of PC1 - Address of PC2 - Address of PC3 - default gatemethod for VLAN10 - default gatemethod for VLAN20 - 1

For us to subdivide the network-related right into two subnets, we need to produce 2 VLANS on the switch, VLAN10 and VLAN20. Give them custom names prefer VLAN 10 - student and VLAN 20 - staff.

To produce two VLANs, we enter the configuration mode using the config terminal command, and also then we enter the VLAN number like vlan 10 together with the name.

Switch>allow !relocating from user exec mode to priviledge modeSwitch#config terminal !relocating from priviledge mode to international configuration modeSwitch(config)#vlan 10 !assigning vlan numberSwitch(config-vlan)#name student !asindications the vlan 10 the name studentSwitch(config-vlan)#exitSwitch(config)#vlan 20Switch(config-vlan)#name staff !asindications vlan 20 the name staffSwitch(config-vlan)#exit
Tip 2Asauthorize switch ports to the VLANS. Ports fa0/1 and also fa0/2 acting as access ports for VLAN10, while ports fa0/3 andfa0/4 for VLAN20.

We shall use fa0/5 port for the trunk port for carrying the traffic between the 2 VLANS through the router.

NOTE: fa refers to rapid ethernet ports provided for connecting the network-related hosts to the switch or router.

Configurations for accessibility ports fa0/1 and also fa0/2

Switch>enable !moving from user exec mode to the priviledge modeSwitch#config terminal !moving from priviledge mode to the global configuration modeSwitch(config)#int fa 0/1 !entering the interconfront portSwitch(config-if)#switchport mode access !making the interconfront fa0/1 an access portSwitch(config-if)#switchport access vlan 10 !making interface accessibility port for vlan 10Switch(config-if)#departure !exiting from the interfaceSwitch(config)#int fa 0/2 !entering the interconfront portSwitch(config-if)#switchport mode access !making the interchallenge fa0/2 an accessibility portSwitch(config-if)#switchport accessibility vlan 10 !making interface access port for vlan 10Switch(config-if)#exit !exiting from the interface
In the configuration above, fa0/1 and fa0/2 are configured as access ports using the command switchport mode access.

Since they belong to vlan10, the switchport accessibility vlan 10 command is offered to connumber them as access ports within vlan10.

Configurations for access ports fa0/3 and also fa0/4

Switch(config)#int fa 0/3 !entering the interconfront portSwitch(config-if)#switchport mode accessibility !making the interchallenge fa0/3 an accessibility portSwitch(config-if)#switchport accessibility vlan 20 !making interchallenge access port for vlan 10Switch(config-if)#exit !exiting from the interfaceSwitch(config)#int fa 0/4 !entering the interconfront portSwitch(config-if)#switchport mode accessibility !making the interchallenge fa0/4 an accessibility portSwitch(config-if)#switchport access vlan 20 !making interconfront accessibility port for vlan 10Switch(config-if)#exit
In the configuration above, fa0/3 and also fa0/4 are configured as access ports making use of the command also switchport mode accessibility.

Due to the fact that they belong to vlan20, the switchport access vlan 20 command also is used to connumber them as access ports within vlan20.

Configurations for trunk port fa0/5

Switch(config)#int fa 0/5 !entering the interchallenge portSwitch(config-if)#switchport mode trunk !making interconfront a trunk port.Switch(config-if)#execute write !saving the running configurations to start-up file
From the over code interconfront, fa0/5 is serving as our trunk port. To configure it to serve as a trunk port and not an access port, we usage the command switchport mode trunk in the international interface mode.

Step 3

Using static IP addressing, set the IP addresses to static on each COMPUTER on the network.


Tip 4

Configure the router to permit the web traffic to relocate from VLAN10 to VLAN20. For the PCs to communicate, we subdivide the single interconfront right into many kind of sub-interencounters, wright here each sub-interchallenge will certainly act as the default gatemeans for each of the VLANs. This will permit 2 sub networks to communicate utilizing the single interconfront.

Router>permit !moving from user exec mode to the priviledge exec modeRouter#config terminal !relocating from priviledge exec mode to the worldwide configuration modeRouter(config)#int g0/0 !entering on our physical router interchallenge gigabitEthernet 0/0Router(config-if)#no shutdown !activating the interfaceRouter(config-if)#int g0/0.10 !initially sub interchallenge for vlan 10 on g0/0Router(config-subif)#encapsulation dot1q 10 !configuring the sub interconfront to respond to web traffic from vlan 10Router(config-subif)#ip include !configuring the IP address of the sub interchallenge g0/0.10Router(config-subif)#leave !exiting from the sub interfaceRouter(config)#int g0/0 !entering our physical rexternal interfaceRouter(config-if)#no shutdown !activating our physical interfaceRouter(config-if)#int g0/0.20 !second sub interface for vlan 20 on g0/0Router(config-subif)#encapsulation dot1q 20 !configuring the sub interconfront to respond to traffic from vlan 20Router(config-subif)#ip include !configuring the IP address of the sub interconfront g0/0.20Router(config-subif)#exitRouter(config)#execute create !saving our running configurations right into the start-up configuration fileRouter(config)#exit
From the configurations over, the interconfront g0/0 is subdivided right into two sub interfaces: g0/0.10 for VLAN10 and also g0/0.20 for VLAN20.

Then, the two sub-interfaces are assigned IP addresses and also serve as the trunk ports for transferring the traffic.

Tip 5

Test the inter-VLAN connectivity by trying to ping the various Computers.

For instance, if we ping PC2 in VLAN20 from PC0 in VLAN10, it must be successful as displayed below:



Inter-VLAN routing is a critical principle for anyone that has actually the passion for netfunctioning. It is the convenient and much better way to subdivide a huge LAN and also to permit communication in between the netjob-related hosts.

You have the right to find more information about inter vlan routing right here.

To summarize:

We learned what VLAN routing is.We explored different techniques to course.We configured the course making use of route-with-stick strategy.

Happy coding.

See more: What Does Naco Mean In Spanish, What Does Naco Mean

Peer Resee Contributions by: Srishilesh P S

About the author
Atonya Dennis

Atonya Dennis is a Computer Technology student at Jomo Kenyatta College Of Agriculture and Technology. His interests are web development and also networking. Dennis has actually a good passion for emerging internet applications and configuring networks.