#8 ROUTING: THE NETWORKING SERIES
Are you online? Of course you are! And that’s how you are reading this blog right now. Would you like to know how this is possible? This series is all about what it takes to be online and access internet!
Hey peeps, it is fun to create peer-to-peer network, but pretty soon, you will want to venture out to other networks and onto the internet. When this time comes, you will be in need of a “router”, which will route your traffic to another networks. Let’s get started!
Routing
In most situations, where we have to connect beyond our local network: out to other homes, businesses and the internet. Devices that are located on other networks that is not a part of your local network is known as “remote hosts”. When a source device sends a packet to a remote destination device, then there comes the need for routers.
Routing is the process of identifying the best path to a destination.
A router is a networking device that connects multiple Layer 3, IP networks. At the distribution layer of the network, routers is used to direct traffic and perform other functions critical to make the network operation efficient. Like switches, routers can also decode and read the messages that are sent to them. But unlike switches, which make their forwarding decision based on the Layer 2 MAC address, routers make their forwarding decision based on the Layer 3 IP address.
The packet format contains the source IP address and destination IP address, as well as the message being sent between them. The router reads the network portion of the destination IP address and uses it to find the best way to forward the message.
If the network portion of the IP addresses of the source and destination hosts do not match, a router must forward the message to the correct network. For example, if a host located in the network 1.1.1.0 wants to send a message to a host located in the network 3.3.3.0, the host will forward the message to the router. Then the router receives the message, de-encapsulates the Ethernet frame, and then it reads the destination IP address in the IP packet. Then the router determines where to forward the message. It then re-encapsulates the packet back into a new frame, and forwards the frame on to its destination.
Why we need routing?
As the network grows, often it is necessary to divide one access layer into multiple access layer networks. There are different criteria in which the network can be divided:
- Broadcast containment
- Security requirements
- Physical locations
- Logical grouping
The distribution layer connects these independent local networks and controls the traffic that flows between them. It is responsible for ensuring that the traffic between the hosts of the local network stays local. Only the traffic that is destined for other networks are passing on. The distribution layer filters incoming and outgoing traffic for security and traffic management.
The networking devices that are in the distribution layer is designed to interconnect networks, not individual devices. Individual hosts are connected to a network via access layer devices, such as switches. The access layer devices are connected to each other via the distribution layer devices, such as router.
Stay connected!!
Check out the Next part
Previous part
