Routing

Routing is the process of taking a packet from one network device, sending it through the network to another device on a different network. Communications across the Internet is one of the best examples of routing.

 The connection of WANs and LANs to a network router and configuring it with logical network addresses (IP address) to all the host on the internetwork to enable communication across the network is a form of routing.

To enable routing between inter-networks, you need a router. If your network has no router it means you not routing and cannot deliver a packet from one inter-network to another.



 Router

Routers are generally known as intermediate systems, which operates at the network layer of the OSI reference model, routers are devices used to connect two or more networks (IP networks) or a LAN to the Internet.

The router is responsible for the delivery of packets across different networks. The destination of the IP packet can be a web server in another country or an e-mail server on the local area network. It is the responsibility of the router to deliver those packets in a timely manner.

The effectiveness of internetwork communications depends on the ability of routers to forward packets in the most efficient way possible.

ROUTER

ROUTER1

Routers are now being added to satellites in space. These routers will have the ability to route IP traffic between satellites in space in much the same way that packets are moved on Earth, thereby reducing delays and offering greater networking flexibility.



Router and Routing Delivery Methods

Router and Routing delivery differ in how they deliver messages from source to destination. There is various type of messages and how they are delivered.

There are:

Unicast: This are messages delivered to a single specific node

Anycast: a message to anyone out of a group of nodes, typically the one nearest to the source

Multicast: a message to a group of nodes that have expressed interest in receiving the message

Geocast: a message to a geographic area

Broadcast: a message to all nodes in the network

However, the routing of traffic/packet through a network can be in the form of static or dynamic routing.

In static routing, these are routing of traffic that normally exists within a small network with  limited topology, usually configured and managed manually by the network administrator or IT person.

In dynamic routing, this involves routing of packet/messages through a larger network with complex topologies that can change rapidly.

Its proven to be difficult and huge time consuming to be managed manually, the success of this type of network maintenance is largely due to the deployment of distance routing protocols and algorithms.

These routing protocols are used to solve the problem of constructing and analyzing routing tables automatically based on information received…

Routing protocols enable an enterprise network to function nearly autonomously in avoiding network failures and blockages.

Examples of dynamic-routing protocols and algorithms include Routing Information Protocol (RIP), Open Shortest Path First (OSPF), Enhanced Interior Gateway Routing Protocol (EIGRP) and Border Gateway Protocol (BGP)

Advantages of a Router

In addition to packet forwarding, a router provides other services as well. To meet the demands on today’s networks, routers are also used :

i. To ensure steady, reliance availability of network connectivity. Routers use alternative parts in the case the primary part fails to the delivery of packets.

ii. To provide integrated services of data, video, and voice over wired and wireless networks.

For security, router helps in mitigating the impact of worms, viruses, and other attacks on the network by permitting or denying the forwarding of packets.

Cisco Routers

Cisco Routers Bootup Process Explained

Basic Cisco Router Configuration

IP Routing Protocols

Difference between Routers, Switches, Hubs and Access Points.