IP Routing is the process during data packets are forwarded from one node to another node on a network until they reach their destinations from source. Generally, Routing is the process of learning or choosing path for traffic in a network. Routing process is applied in many different networks such as Circuit Switched Network, Public Switched Network, and Computer Network, this computer network such as internet.
When amount of data is transferred from one machine to another machine on same network related to IP address, the transferred data is divided in to small parts or units called packets. This smaller packet consists of data useful when traveling to their destination, as you know that hundreds and thousands of data packets are transferred from source to destination in a single second and this because of fast sorting process in that device.
Switching is same as IP Routing but switching have very small technical differences, in IP routing IP packets are forwarded from source to destination, and IP learns packet switching in comparison with that circuit switching, The IP Routing protocols give access to create a routers table that helps data packets to reach final destination, these protocols include Border Gate way Protocol (BGW), Intermediate system to intermediate system (IS – IS), Open Shortest Path First (OSPF), Routing Information Protocol (RIP). Generally in routing process data packets are forwarded on the basis of routing tables which maintain set of routs to travel network destinations.
How IP Routing Works:
IP Routing works just like as sending a message data to another person through internet, this messaged data packets passes through lots of routers to reach their destination this process is also known as routing.
Here each data packet carries certain amount of data such as IP address of source and destination location to reach their destination. Generally each router consists of routing table about data of other router or about neighboring router. The each data packets are travels in different ways and passed through different networks and take different paths based on their routing tables but finally reach same. After reaching the destination, the destination address and device address will match. The data packets are taken by the device where IP module on it will re-assemble them and send final data to TCP for next step of processing.
Transmission Control Protocol TCP and IP works together to check weather transmission of data is correct or not and to ensure no data packet is lost. And there is no unwanted delay in transmission of data packets. Sometimes TCP is replaced by User Datagram Protocol (UDP) which does not sure in transmission of data and just transmits data packets, Some VoIP devices uses User Datagram Protocol for making calls and lost packets does not affect the call quality.
Types of IP Routing:
Routing is performed in network layer of a device in order to transfer packets by choosing optimal path to reach destination. There are three types of routing named as
- Static Routing.
- Default Routing.
- Dynamic Routing.
Static IP Routing:
Static routing is the process in which routing table is manually specified by network administrator, so in static routing network administrator have to modify routing manually. Generally, static routing can be implemented in small networks as dynamic will be implemented in large networks. Static routing provides high security of data transmission between two devices. If there is any link failure in static routing then it obstructs the rerouting. And static routing is also known as non-adoptive routing, this non-adoptive routing enables a pre-computed route to be fed into the routers offline.
Example for Static route: hostname(config)# route outside 10.10.10.0 255.255.255.0 192.168.1.1 
Default IP Routing
Default routing is a process in which the router is configured to transfer all packets to a single router and it identifies Gate way IP address to which ASA sends all IP packets, a default route is same as static root with 0.0.0.0/0 as destination IP address. Generally, it is used in stub routers which has only one route to reach all other destination networks.
Example for Default route: hostname(config)# route outside 0 0 192.168.2.4
Dynamic IP Routing:
Dynamic routing is the process in which routes are automatically adjusted on the basis of a current state of the route in the routing table. dynamic routing is implemented by using IP Routing Protocols. Dynamic routing uses extra protocols to discover network destinations. Here Routes are updated according to change in topology and the dynamic route is generally used in large networks as static routing is used in smaller networks. Routing protocols such as RIP, EIGRP, etc are involved in the routing process. So RIP and OSPF is the best examples of dynamic routing.