CCNA Bangla Tutorial 05: What Is Inter-VLAN? Router-on-a-Stick Inter-VLAN Routing configuration

VLANs are used to segment switched Layer 2 networks for a variety of reasons. Regardless of the reason, hosts in one VLAN cannot communicate with hosts in another VLAN unless there is a router or a Layer 3 switch to provide routing services.

Inter-VLAN routing is the process of forwarding network traffic from one VLAN to another VLAN.

CCNA Full Course:

CiscoPress: https://www.ciscopress.com/articles/article.asp?p=3089357&seqNum=4

There are three inter-VLAN routing options:
1. Legacy Inter-VLAN routing: This is a legacy solution. It does not scale well.
2. Router-on-a-Stick: This is an acceptable solution for a small- to medium-sized network.
3. Layer 3 switch using switched virtual interfaces (SVIs): This is the most scalable solution for medium to large organizations.

he “router-on-a-stick” inter-VLAN routing method overcomes the limitation of the legacy inter-VLAN routing method. It requires only one physical Ethernet interface to route traffic between multiple VLANs on a network.

A Cisco IOS router Ethernet interface is configured as an 802.1Q trunk and connected to a trunk port on a Layer 2 switch. Specifically, the router interface is configured using subinterfaces to identify routable VLANs.

The configured subinterfaces are software-based virtual interfaces. Each is associated with a single physical Ethernet interface. Subinterfaces are configured in software on a router. Each subinterface is independently configured with an IP address and VLAN assignment. Subinterfaces are configured for different subnets that correspond to their VLAN assignment. This facilitates logical routing.

When VLAN-tagged traffic enters the router interface, it is forwarded to the VLAN subinterface. After a routing decision is made based on the destination IP network address, the router determines the exit interface for the traffic. If the exit interface is configured as an 802.1Q subinterface, the data frames are VLAN-tagged with the new VLAN and sent back out the physical interface.

source

by TecH Bangla 2.0

windows server dhcp vlan