Difference between Dynamic Routing and Static Routing Comparison

Difference between Dynamic Routing and  Static Routing Comparison 

This article explained dynamic routing and then we learn about difference between Dynamic Routing and  Static Routing. In a large network with many networks and subnets, the configuration and maintenance of static routes between these networks entail an administrative and operational overhead . This administrative overhead is especially tedious if changes occur in the network, such as an out-of-service link or the implementation of a new subnet. Implementing dynamic routing protocols can ease the burden of configuration and maintenance tasks, in addition to providing scalability to the network.

Dynamic Routing Protocols

Dynamic routing protocols have been used in the field of networks since the late 1980s. One of the first routing protocols was the RIP . RIPv1 was launched in 1988, but already in 1969 some of the basic algorithms in that protocol were used in the Advanced Research Projects Agency Network (ARPANET).
As the networks evolved and became more complex, new routing protocols emerged. The RIP protocol was updated to RIPv2 to make room for growth in the network environment. However, RIPv2 is not yet implemented to larger networks today. In order to meet the needs of larger networks, two routing protocols were developed: the OSPF protocol (first open the shortest route) and intermediate system to intermediate system (IS-IS). Cisco developed the internal gateway routing protocol ( IGRP ) and Enhanced IGRP ( EIGRP ), which also has good scalability in larger network implementations.
Also, the need arose to connect different internetworks and provide routing between them. Currently, the Border Gateway Protocol ( BGP ) is used between Internet service providers (ISPs). The BGP protocol is also used between ISPs and their largest private clients to exchange routing information.

Classification Table of Dynamic Routing Protocols.

Interior Gateway Protocols	External Gateway Protocols
IPv4 : RIPv2, EIGRP, OSPFv2, IS-IS	IPv4 : BGP-4
IPv6 : RIPng, EIGRP for IPv6, OSPFv3, IS-IS for IPv6	IPv6 : BGP-MP

Components of Dynamic Routing Protocols

Routing protocols are used to facilitate the exchange of routing information between routers. A routing protocol is a set of processes, algorithms and messages that are used to exchange routing information and complete the routing table with the choice of the best paths that the protocol performs.
The purpose of dynamic routing protocols includes the following:

• Discover remote networks
• Keep routing information updated
• Choose the best path to destination networks
• Be able to find a better new road if the current route is no longer available

The main components of dynamic routing protocols include the following:

1. Data structures : routing protocols generally use tables or databases for their operations. This information is saved in RAM.
2. Routing protocol messages : Routing protocols use various types of messages to discover neighboring routers, exchange routing information and perform other tasks to discover the network and keep accurate information about it.
3. Algorithm : an algorithm is a finite list of steps that are used to carry out a task. Routing protocols use algorithms to provide routing information and to determine the best path.

Routing protocols determine the best route to each network and then that route is offered to the routing table. The route will be installed in the routing table if there is no other routing source with a smaller administrative distance. For example , a static route with an administrative distance of 1 will have priority over the same network discovered by a dynamic routing protocol

Comparison between Dynamic Routing and  Static Routing

Dynamic routing definitely has several advantages over static routing, however, static routing is still used in networks today. In fact, networks generally use a combination of static and dynamic routing.
Static routing has several main uses, including:

• It facilitates the maintenance of the routing table in smaller networks in which they are not expected to grow significantly.
• Routing to and from an internal route network , which is a network with a single default route out and without knowledge of remote networks.
• It allows access to a single predetermined route (which is used to represent a route to any network that does not have a more specific match with another route in the routing table).

Advantage and Disadvantage of Static Routing:

In the following table, the advantages and disadvantages of static routing are highlighted. Static routing is easy to implement in small networks. Static routes remain unchanged, which makes it relatively easy to solve problems. Static routes do not send update messages; therefore, they cause very little overhead.

Advantages	Disadvantages
Easy to implement in small networks	Suitable only for simple topologies or for specific purposes, such as a default static route.
Very sure. No ads are sent, unlike the case of dynamic routing protocols.	The complexity of the configuration increases markedly as the network grows.
The route to the destination is always the same.	Manual intervention is required to re-route traffic.
Since no routing algorithms or update mechanisms are required, no additional resources (CPU or RAM) are needed.	-

Uses of  Dynamic Routing 

Dynamic routing protocols help the network administrator to manage the rigorous and slow process of setting up and maintaining static routes.
Imagine having to maintain static routing configurations for the seven routers in the following figure.

What would happen if the company grew and now had four regions and 28 routers to manage, as shown in the following other figure? What happens when a link stops working? How do you ensure that redundant routes are available?

Dynamic routing is the best option for large networks like the one shown.

Advantage and Disadvantage of Dynamic Routing:

In the following table, the advantages and disadvantages of dynamic routing are highlighted. L os dynamic routing protocols work well in any type of network consists of several routers . They are scalable and automatically determine the best routes if a change in the topology occurs. Although there are other aspects to take into account regarding the configuration of dynamic routing protocols, they are simpler to configure than static routing in large networks.

Advantages	Disadvantages
Suitable in all topologies where several routers are required.	The implementation can be more complex.
It is usually independent of the size of the network.	Less safe. Additional configuration options are required to provide protection.
If possible, automatically adapt the topology to re-route traffic.	The route depends on the current topology.
-	Requires additional CPU, RAM and link bandwidth.