A protocol that provides the information that is needed by the Network layer or Layer 3 of Open System Interconnection (OSI) reference model. The network layer needs source and destination address to forward the packet to the destination. The address needed for the network layer is provided by the Routed Protocols.
Routed protocol defines the addressing scheme and sub networks of a host. Addressing schemes helps to determine the network to which a particular host belongs. Routed protocol helps an administrator to identify a particular host in a network. Routed protocols are sent on a routed network.
Internet Protocol (IP), IPX, SNA, AppleTalk is few examples of routed protocols. Internet protocol (IP) is widely used routed protocol. The routed protocol has both network and host parts in it. Internet Protocol has two versions IPv4 and IPv6.
Ipv4, connection less protocol, used in packet switching networks. IPv4 uses 32 bits to generate an address for any host on the network.
IPv4 is divided into five classes. The classes are divided based on number of hosts each network allows. Using IPv4 we can generate 232 addresses. With the growth of internet, these addresses are endangered to exhaustion.
Hence IPv6 came into existence. IPv6 uses 128 bits to generate a address to a single host. Hence we can generate 2128 addresses using IPv6.
The routing protocols are used to define the communication way among the routers. The routing protocols advertise the information about the devices that are connected over the network.
These protocols automatically update the router about the devices that are connected in the network. The router based on the information given by the routing protocols maintains routing table. When a packet reaches router, it checks for the destination IP address and verifies the routing table to find the best path and forwards the packet.
The best path is decided by considering various metrics like Administrative Distance, Bandwidth and Congestion etc. If there is a change in the topology in the network, the information is automatically updated among the routers.
This reduces the task of an administrator to manually update in every router whenever there is a change in the topology. Some of the routing protocols are Router Information Protocol (RIP), Open Shortest Path (OSPF) and Enhanced Interior Gateway Protocol (EIGRP) etc.
All the routing protocols are divided into Link state routing protocols, distance vector routing protocols and hybrid routing protocols.
- Configuring serial interface in cisco router
- What is Routing and Switching
- Different Types of Routes, Static Routes and Dynamic Routes in Routing
- Differences between Routable protocols and Non routable protocols