Process of IP routing in router
The process of transferring packets across various networks through an IP router is known as the IP Routing Process. Data packets are sent and received by the IP Routing Process in routers whenever we connect to the internet or an intranet.
There is a separate network for each router interface. Layer 3 devices are another name for routers. The transfer of data packets between various networks is facilitated by a number of routing protocols. In most routers, static routing, default routing, and dynamic routing protocols handle the IP routing process.
Need for an IP Routing Process in a Router
The purpose of a router is to transfer data packets from one interface to another interface, or more importantly, between separate networks. This is the function of a router. The transfer of data packets that takes place at the third layer of the OSI reference model, which is referred to as the network layer. The router maintains a routing table that contains information about the neighboring routers and networks.
It is possible for a router to have a large number of interfaces that could connect several networks. The routing protocol and the procedure that the router uses to move the packet to its destination are both dependent on the router. In the context of a router, the term “static route” refers to a collection of protocols that enable the router to send a packet to its intended destination. In order to have a complete understanding of the IP Routing Process in a router, it is important to first have knowledge of the routing protocol and the routed protocol.
IP routing protocols in routers, routing process
Routing Protocols make it easier for routers to create and update their routing tables. The default routing in routers relies on routing protocols. Routing Protocols provide the router with information regarding the networks that are linked to each interface. Data packets are not carried or pushed in any way by routing methods. It was necessary to update the routing tables of every router whenever there was a change in the network. The routing protocols handle this responsibility. In order for routers to choose the optimal way to send data packets out, routing protocols are used.
Routing protocols include IGRP, OSPF, RIP, RIPv2, and others. Distance vector, link state, and hybrid protocols are the subcategories of routing protocols. Every router in the network has its routing table updated by these protocols. Use the “show ip route” command to view the routes. When it comes to the flow of data packets, routing techniques are completely blameless. Protocols for routing disseminate the details of a network’s structure to each and every router.
Routed Protocol for IP Routing process in a router
Routed protocol is used by default in routers to route data packets. Routed protocol sends the data packets through the ports of a router. What is the best way for the packets? The routing protocol figures that out and sends them along that path. Router ports are where routed protocols are set up. Routed protocols don’t change or take care of a router’s routing table. Data packets move from one network to another network with the help of routed protocols.
The data packets are transmitted to the appropriate exit interface of the router by means of routed protocols. Interfaces of the router are where the configuration of routed protocols takes place. IP, IPv6, IPX, and Appletalk are all examples of protocols that allow for routing. By their very nature, routed protocols are essentially the addressing schema of the router’s interfaces. A router is responsible for determining the network that a data packet is intended for and then sending the data packet to the appropriate exit interface. Specifically, routed protocols are where the idea of subnetting is implemented.
A brief explanation of the router’s IP routing process
Using the IP routing procedure in the router, data packets are transferred between two separate networks. It is a router that is responsible for transferring data packets between several networks. The transport of data packets between the interfaces of routers is achieved through the utilization of a number of different protocols. Let’s talk about the IP routing mechanism in router by using a very simple network design as an example. The network was designed in the manner seen in the next illustration. A router is used to establish a connection between two distinct networks, namely 192.168.10.0/24 and 192.168.20.0/24. An example of the routing of ICMP packets between the two networks is shown here.
See the picture above. PC1’s IP address is 192.168.10.5/24, and its gateway is 192.168.10.1. 192.168.10.1 is the IP address of GigabitEthernet0/0/0. In the same way, PC2’s IP address is 192.168.20.5/24 and its gateway is 192.168.20.1. 192.168.20.1 is the IP address of GigabitEthernet0/0/1. Once the above IP addresses are set up, PC1 can ping PC2 without having to set up any forwarding. PC1 and PC2 can talk to each other because both networks are directly linked to the router. In the router, type “sh ip route” to see the list of connected networks.
Router#show ip route
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default, U - per-user static route, o - ODR
P - periodic downloaded static route
Gateway of last resort is not set
192.168.10.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.10.0/24 is directly connected, GigabitEthernet0/0/0
L 192.168.10.1/32 is directly connected, GigabitEthernet0/0/0
192.168.20.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.20.0/24 is directly connected, GigabitEthernet0/0/1
L 192.168.20.1/32 is directly connected, GigabitEthernet0/0/1
The results of the connected networks with the router are displayed above for your perusal. PC1 is able to provide a ping to PC2. In this section,we will walk you through the process of how Ping operates through the IP routing procedure in the router. The Ping command is used to send and receive ICMP packets from a device specified as the destination. PC1 is the source, and PC2 is the destination in this scenario. During the entirety of the communication that takes place between PC1 and PC2, the following IP routing mechanism takes place.
The first step in the router’s IP routing process
When the command ping 192.168.20.5 is issued in PC1, an ICMP packet is generated. The IP address 192.168.20.5 is the one that this ICMP packet is trying to find. Because this IP address is not available on the local network, PC1 sent out an ARP request through broadcast to get the mac address in the network. In response to the request, the router sent the GigabitEthernet0/0/0 interface’s mac address.
