What Is Dynamic Routing And Why Does It Play Such An Important Role In The World Of Computer Networks? Routing Refers To Choosing The Best Route In Internal And External Networks.
Data is sent along the shortest, most optimal route to the destination. Based on this definition, routing is the process of finding the optimal path to transfer packets between network interfaces.
Dynamic Routing
Routers manage the process described above, which is a basic requirement in the network world. Routers use routing tables and algorithms to manage packets’ routing and transfer to nodes within a local area network or a public network (Internet).
Routing in the world of computer networks
In computer networks, routing is done in two ways: static and dynamic. Static routing is based on the IP path or the default path. In the first case, routers can use manually configured routing table entries configured by the network administrator to send packets, or use routing information provided by dynamic routing algorithms.
The essential advantage of using a static routing model is the lower bandwidth usage compared to dynamic routing.
However, this mechanism does not work well for large networks, as the network administrator must manually configure all settings, which is time-consuming. In contrast to static routing, dynamic routing is used. Dynamic routing allows the routing table to maintain these changes when the router is turned off or unavailable, or a new network is added to the existing network.
In the dynamic routing process, packets can be continuously exchanged between nodes through routing protocols, the status of each network router can be checked, and subnet nodes can use approaches such as multicast to exchange information.
And constantly update the routing table information. In this case, the routers’ routing tables are updated continuously. The most crucial dynamic routing protocols include OSPF, EIGRP, IGRP, and IS-IS.
These protocols are classified into three groups:
Link State, distance vector, and Hybrid Routing. In the dynamic routing process, packets can be continuously exchanged between nodes through routing protocols, the status of each network router can be checked, and subnet nodes can use approaches such as multicast to exchange information.
These protocols are classified into three groups:
What do routing protocols do?
Routing protocols are used to build routing tables and decide on the best route. Today, various dynamic routing protocols are available to network experts, among which the most important are OSPF, EIGRP, IGRP, and IS-IS. In general, a routing protocol defines how nodes communicate with each other and how they manage information transfer.
A routing protocol enables nodes to choose the best route to exchange information. Network nodes and routers only know about the networks to which they are connected.
A routing protocol shares the information that routers need between close neighbors and across the network. In this way, routers gain the necessary knowledge through routing tables.
Distance-Vector Routing Protocols
Vector-distance routing protocols use the Hop Count metric, which specifies the number of routers along a path. These protocols send their routing tables directly to all neighboring nodes at specified intervals, with high bandwidth. When a route becomes inaccessible, all network routers must update their routing tables based on new information.
The problem with vector-distance protocols is that each router must report new information to neighboring nodes. It takes a long time for all routers to obtain accurate network information. Vector-distance protocols use a fixed subnet mask that lacks scalability.
The algorithm on which these protocols work and create routing tables uses simple mathematical calculations.
In general, vector-distance protocols are used for small networks with fewer than 16 routers. Vector-distance protocols standardize router routing tables at specified intervals and use two distance and direction metrics to find the destination.
Routers that use vector-distance routing protocols provide their neighboring routers with information about the network topology and changes over time.
This notification is based on the Broadcast approach and the IP address 255.255.255.255. Vector-distance protocols use the Bellman-Ford algorithm to find the shortest path to a destination.
Routers that use protocols in this family send a broadcast request to their neighbors to obtain the routing table information of neighboring routers.
In addition, they use the Broadcast technique to share routing table information.
Vector-distance algorithms. Whenever a change is made to the routing table, the information is immediately sent to all router interfaces for full distribution.
In this case, the distance value of the received route increases and replaces the previous distance value. This process continues to update the routing tables of all routers.
As you can see, vector-distance protocols are the simplest type of routing protocol, easy to identify and troubleshoot, but they consume a significant amount of network bandwidth.
Link State Routing Protocols
Link-state protocols operate quite differently from distance-vector protocols and have their own complexities. Link status is a unique routing protocol that provides routers with a complete roadmap. Routers that use the link-state protocol can route packets without problems because they have a full picture of the network.
Using link status protocols is to find the best route to the destination based on different patterns. Link status protocols publish routing information only whenever changes are made to use bandwidth more efficiently and accurately.
In this case, instead of the routing table, routers emit only changes that significantly reduce the extra network traffic and increase data exchange speed.
Routers that use the link-state protocol always have first-hand information from all routers, since each router maintains a routing table. The links connected to it create the status of the links and transmit the above information to another router.
In this mechanism, each router has a copy of the information without altering it.
Link status protocols are known by various names, such as Distributed Database Protocol or Shortest Path First. Link link status routing protocols use an algorithm called Dijkstra to determine the best path.
Routers that use link-state protocols only need to unify their routing tables when a new entity is added to one of them. For this reason, they consume the least traffic when unifying the routing table.
In connection routing protocols, routers provide the network with comprehensive information about themselves, including direct links to them and the status of the links.
The information is sent to all routers on the network via the multicast approach, which is the exact opposite of the vector-distance protocol approach.
In the connection status routing process, changes are sent to all routers whenever there is a slight change in the network configuration.
In the above architecture, each network router has a copy of the network connection and independently calculates the best routes to reach the destination networks.
Linkage status protocols based on the Shortest Path First (SFP) algorithm select the most appropriate route to reach the destination. In the above algorithm, whenever the status of a communication link changes, a path update called the LSA (Link State Advertisement) is generated and sent to all routers.
This group’s necessary routing protocols include OSPF and IS-IS on the IP platform, CLNS, and NLSP.
The OSPF protocol, also known as the Interior Gateway Protocol, is one of the most popular family protocols (IGPs).
OSPF is the standard for IP routing in large networks.
When the OSPF protocol is configured on the network, it listens to nearby routers and gathers data packets sent by those routers to create a map of all available routes.
When a router configured with OSPF is launched, hello packets are sent to all OSPF routers on the network. Hello, packets include information such as router timers, unique identifiers, routers, and subnet masks. The data stored in the databases calculates the best and shortest possible path to each subnet or core network using the SFP algorithm.
Hybrid routing protocols
Hybrid routing protocols combine vector-distance and Link-State protocols to achieve optimal performance and leverage each protocol’s strengths.
More precisely, they use the capabilities of vector-distance protocols (due to lower processing requirements) when they need processing power, and the capabilities of link-status protocols when exchanging routing tables across the network. Given their potential benefits, hybrid protocols are used in large networks.
One of the most famous protocols in this group is EIGRP. EIGRP can route IP, IGRP, and AppleTalk protocols and uses hybrid metrics, similar to IGRP, to select the best route to the destination.
FAQ
What is dynamic routing?
Dynamic routing is a method where routers automatically exchange information and update their routing tables to pick the most efficient path for data based on the current network state.
How does dynamic routing differ from static routing?
Static routing uses manually configured, fixed paths that don’t change unless adjusted by an administrator; dynamic routing adapts automatically to network changes using routing protocols and algorithms.
What are the main advantages of dynamic routing?
It allows for automatic adaptation to link failures or network changes, supports larger and more complex networks, provides redundancy and load-balancing, and reduces the need for manual route management.