The router function in a computer network is to do the routing. Routing itself consists of several kinds. One of the many routing routines used in computer networks is dynamic routing. What is dynamic routing? How does the work of dynamic routing? Here we explain about dynamic routing for you
1. Understanding Dynamic Routing
Dynamic routing is the routing done by the router by way of making the data communication path automatically in accordance with the settings made. If there is a change in topology within the network, then the router will automatically create a new routing path. This dynamic routing resides in the network layer network of the computer network in TCP / IP Protocol Suites.
Dynamic routing is a routing protocol used to locate networks and to update routing tables on routers. This dynamic routing is easier to do than using static and default routing. However, this type of routing has differences in data processing in the router CPU and bandwidth usage of network links
2. Advantages and Disadvantages of Dynamic Routers
Compared to the disadvantages and advantages of static routing with dynamic routing, you are better off choosing dynamic routing in applying on a large enough network. Dynamic routing has several advantages, including:
- Only introduce addresses directly connected to the router (network under the control of the router).
- No need to know all existing network addresses
- If there is an addition of a network new, then all routers do not need to configure. Only router-related router that will reconfigure
While the dynamic routing loss is as follows:
- Router workload becomes more severe because it always update the IP table at any given time.
- The speed of recognition and completeness of IP table take a long time because the router will broadcast to all routers until there is a suitable IP table. After the configuration is complete, the router must wait for a while to have each router get all the IP addresses available.
3. Various Protocols on Dynamic Routing
Along with the development of the history of computer networks there are many different kinds of protocols in dynamic routing applied today, among them as follows:
RIP (Routing Information Protocol)
RIP is a protocol that provides routing tables based on directly connected routers. Then, the next router will provide information to the next router that is connected directly with the router. The information provided in the RIP protocol is: host, network, subnet, and route default. Oh yes, let's see our discussion about routing table function on router so that you understand the meaning of this paragraph.
This routing uses distance vector algorithm. Metrics are performed based on the hop count for the selection of the best path. If the hop count is more than 15, then the datagram packet will be discarded. Routing updates will be broadcasted every 30 seconds.
RIP is divided into two parts:
- RIPv1 (RIP version 1)
- No subnet info entered in routing repair data
- Does not support VLSM (Variable Length Subnet Mask)
- There is a feature of broadcast routing fixes
In general, RIPv2 does not vary much with RIPv1. The differences are visible in the information provided between routers. In RIPv2, the information exchanged is authenticated. There is still another RIPv2 equation with RIPv1, including:
- Distance Vector Routing Protocol
- Metric of hop count
- Max hop count is 15
- Using port 520
- Running auto summary by default
the difference between RIPv2 and RIPv1 is as follows:
- A class-less routing protocol, which means RIPv2 includes a SM field in the update packet sent so RIPv2 can support VLSM & CIDR
- Submit the update package & receive the update package version 2  Submit an update to a multicast address that is 188.8.131.52
- Auto Summary can be disabled
- Supports security functions of authentication, which can prevent routing updates sent / received from unbelievable sources
IGRP (Interior Gateway Routing Protocol)  IGRP is a routing protocol developed in the mid-1980s by Cisco Systems Inc. The main purpose of IGRP creation is to provide a robust protocol for routing within an autonomous system. IGRP has a maximum hop of 255, but the default itself is 100. IGRP uses bandwidth and delay lines by default to determine the best route in an internetwork (Composite Metric). This routing protocol uses distance vector algorithm. IGRP uses composite metrics consisting of bandwidth, load, delay and reliability. Routing updates are broadcasted every 90 seconds.
In IGRP, routing is mathematically based on distance. To that end, the IGRP system has considered several things before deciding which route to take. As for things to note include: load, delay, bandwitdh, realibility. Because the protocol was created by Cisco, then in the Cisco basic commands there is a command to govern this protocol.
OSPF (Open Short Path First)
OSPF is an open standard routing protocol that has been applied by a number of network vendors and described in RFC 2328. If you have multiple routers, and not all of them are Cisco routers, then you can not use IGRP. so your choice to stay RIP v1, RIP v2, or OSPF. If the managed network is a large network, then OSPF is the only option. This OSPF is something called route redistribution, which is a translation service between routing protocols.
OSPF works with a link-state algorithm called the Dijkstra / SPF algorithm. The workings of this protocol are: First, a "tree" with the shortest path will be built. Then, the routing table will be populated with the best paths generated from the "tree". OSPF only supports IP routing only. The routing update will be floaded as network topology changes.
EIGRP (Enhanced Interior Gateway Routing Protocol)
This routing protocol uses advanced distance vector algorithms and uses unequal cost load balancing. The algorithm used is a combination of distance vector and link-state, and uses Diffusing Update Algorithm (DUAL) to calculate the shortest path.
Distance vector protocol maintains a complex set of metrics for distance to other networks. EIGRP broadcasts are updated every 90 seconds to all adjacent EIGRP routers. Each update only includes network changes. EIGRP is perfect for large computer networks. IGRP and EIGRP have both considered the existing bandwidth problems and delays that occur.
BGP (Border Gateway Protocol)
BGP is one type of routing protocol in the world of data communications. As a routing protocol, BGP has the ability to collect routes, exchange routes and determine the best route to a location within a network. Routing protocols must also be equipped with intelligent algorithms in finding the best path. But what distinguishes BGP from other routing protocols is that BGP belongs to the category of routing protocol type Exterior Gateway Protocol (EGP). BGP is a "distance vector exterior gateway protocol" that works intelligently to maintain paths to other networks. Updates – updates will be sent over a TCP connection. This protocol is commonly used between ISPs with ISPs and or between clients with other clients. In its implementation, this protocol is used to create routes from internet traffic between autonomous systems
4. Advantages and Disadvantages of Dynamic Routing Protocols
What are the advantages and disadvantages of each of the dynamic routing protocols we have mentioned above? the following explanation:
- Routing Information Protocol (RIP)
- Using the "Triggered Update" method.
- Has a timer to know when routers should return routing information.
- changes in the network, while the time on the timer is not exhausted, the router must still send the routing information because triggered by the change (triggered update)
- Setting the routing using RIP is not complicated and gives fairly acceptable results, especially if the link failure on the network.
- The number of hosts is limited.
- has no information about the subnet of each route
- does not support Variable Length Subnet Masking (VLSM).
- When first run, RIP only knows how to routing itself (local / localhost information) and does not know the network topology where it is located
- Advantages Support to 255 hop count
- Number of restricted hosts
- Open Shortest Path First
- Open Gateway First Route Protocol (IGRP) (OSPF)
- Not producing routing loops
- supporting the use of multiple metrics at once
- could produce multiple paths to a goal of dividing large networks into multiple areas
- Time needed to converge more rapidly
- More complicated
- Enchanced Interior Gatway Routing Protocil (EIGRP)
- Performs precise convergence while avoiding loops.
- Requires less memory and process.
- Features of "loop avoidance"
- Only usable for the Cisco Router
- Exterior Gateway Protocol (EGP)
- Very simple in installation
- Very limited in using network topology
we are this time around dynamic routing. Hopefully our aritkel can increase your knowledge about dynamic routing.