What Is Mean by Routing Protocol
The lower the numerical value of the administrative distance, the more the router trusts the route. The closer the numerical value is to zero, the better. Routing protocols use administrative distance primarily to evaluate the reliability of connected devices. You can change the administrative spacing of the log by using the delete process in subconfiguration mode. When reviewing routing protocols, it is important to first determine which devices on the internal network should receive and send routing information. Most likely, only devices directly connected to the external network should receive and respond to external routing changes, such as gateway routers for the internal network. This is primarily due to the hierarchical nature of route tables, where no external host needs to know the routing specifics of a remote subnet. Therefore, it is usually not necessary to transfer routing information from the external network to the internal network, and vice versa. Standard routing forwards packets without the specific next hop address. The default route is basically the address of another router.
If the address on the package matches the route, the package is transferred. Otherwise, it will be routed through a default route of that router. The packet can be routed through any router configured for standard routing. The dynamic routing protocol allows routers to dynamically learn information about other routers and automatically add the information to the routers` table. The routing protocol determines the best network path added to the route table. For the distance vector packet type for internal routes for IP networks, the type field is set to 0x0102. This type is for route table entry with fields similar to those used in IGRP (compare Figure 5.10 with Figure 5.6). So let`s look at the main differences between EIGRP and other protocols.
A field for the next hop is similar to RIPv2 included in EIGRP. this does not happen in the PRIG. The delay and bandwidth fields have a length of 4 bytes in EIGRP instead of 3 bytes in IGRP because EIGRP uses a multiplier of 256 for a finer metric granularity than IGRP. Therefore, if the composite metric is denoted CIGRP as specified in equation (5.5.1) for IGRP, the composite metric, CEIGRP, for EIGRP can be written as follows: Routers work as follows: When a router receives a packet, it reads the packet headers* to see its intended destination, such as how a flight attendant can check a passenger`s tickets to determine which train to board. It then uses the information in the route tables to determine where to route the packet. Route tables can be static or dynamic. Static route tables do not change. A network administrator manually configures static route tables. This essentially determines the routes taken by data packets over the network, unless the administrator manually updates the tables. This type of routing protocol is best suited for large network sizes, as it broadcasts every 90 seconds and has a maximum hop count of 255. It helps you maintain larger networks compared to RIP. IGRP is also widely used because it is resistant to routing loops as it updates automatically when route changes occur within the specific network.
It also offers an option to load balance traffic via equal or unequal metric cost paths. Convergence with EIGRP is faster because it uses an algorithm called a double update algorithm, or DUAL, that runs when a router detects that a particular route is unavailable. The router polls its neighbors for a viable successor. This is defined as a neighbor with the least expensive route to a specific destination that does not cause routing loops. EIGRP updates its route table with the new route and associated metric. Route changes are only announced to the affected routers when changes occur. This makes bandwidth utilization more efficient than distance vector routing protocols. Although there are many types of routing protocols, three main classes are widely used in IP networks: Before we take a closer look at the TCP/IP routing protocols used to ensure that each router knows how to forward packets closer to their final destination, it`s a good idea to understand exactly what routing protocols are trying to achieve on the modern Internet. Today`s Internet consists of nested pieces of network, much like a puzzle of global proportions. Each piece is called a standalone system (AS), and it`s convenient to think of each ISP as AS, although that`s not true per se. Many routing protocols are defined in standard technical documents called RFCs. [3] [4] [5] [6] The routing algorithm is nothing more than the software that helps determine the optimal path for packet transmission.
Routing is one of the most basic areas of the network that an administrator needs to know. Routing protocols determine how your data gets to its destination and help make this routing process as smooth as possible. However, there are so many different types of routing protocols that it can be very difficult to follow! IGRP is a protocol designed to coordinate routing between a number of routers. There are a number of routing destinations using Cisco`s IGRP protocol: RIPv1 interacts with the network by sending its IP table to all routers connected to the network. RIPv2 is a bit more sophisticated and sends its routing table to a multicast address. RIPv2 also uses authentication to further secure data and chooses a subnet mask and gateway for future traffic. The main limitation of RIP is that it has a maximum number of hops of 15, making it unsuitable for large networks. The Open Shortest Path First or OSPF protocol is a link-state IGP suitable for IP networks using the Shortest Path First (SPF) algorithm. The SPF routing algorithm is used to calculate the tree covering the shortest path to ensure efficient packet data transfer. OSPF routers maintain databases that list information about the surrounding network topology.
This database is populated with data obtained from Link State Advertisements (LSA) sent by other routers. LSAs are packages that contain information about how many resources a given path would require. RIPv2 is a bit more sophisticated because it sends its routing table to a multicast address. RIP: The Routing Information Protocol (RIP) uses hop count to find the shortest path from one network to another, where “hop count” means the number of routers a packet must pass through along the way. (When a packet passes from one network to another, it is called a “hop.”) Some network certification courses distinguish between routing protocols and routed protocols. A routed protocol is used to deliver application traffic. It provides appropriate address information to its Internet layer or network layer so that a packet can be routed from one network to another. Examples of routed protocols include Internet Protocol (IP) and Internetwork packet exchange (IPX). RIP v2 is a distance vector protocol that supports VLSMs. Low overhead, i.e.
IGRP should not use more bandwidth than necessary for its own use The Interior Gateway Routing Protocol (IGRP) was developed by Cisco to solve problems related to RIP on large networks.