This is to even be considered in the load balancing process. There are two things you must be aware of when using eigrp unequalcost load balancing, and well cover those and a whole lot more in this lab in the previous lab, we saw equalcost load balancing in action. Download cisco ccnp routing pdf study guide snabay networking. In the event of a duplicate rid, the neighbors routes will not be installed. But generally, something is wrong with your output, path via 192. Configure and verify unequalcost load balancing with eigrp. Eigrp, all you need to know for the ccna learn how enhanced interior gateway protocol eigrp works and how your network can benefit from it free ccna course networking fundamentals routing written by alessandro maggio. Use show and debug commands for the eigrp topology table. Eigrp supports unequal metric load balancing, which allows administrators to better distribute traffic flow in their networks. Manual summarization can be enabled at any interface. Bgp cisco configuration cisco products cloud comparison configuration dhcp eigrp high availability ip packet ip routing ipv6 ip voice juniper configuration juniper routing juniper security lan technologies layer 1 load balancing monitoring and management mpls multicast nat network design network.
Identify successors, feasible successors, and feasible distances. Now its time to do a little unequalcost balancing, using this network. For load balancing, eigrp will by default install up. Eigrp can load balance on both equal and unequal cost paths. Load balancing with eigrp routing table cisco certified.
Mar 24, 2014 many of you have problems finding a comprehensive guide to load balancing for eigrp. Lets take a look at an example of how eigrp can do load balancing. Variance command is used to configure load balancing. Recently, i was asked a question regarding traffic load balancing across several links and i was able to provide two options that i thought would work. It is a free software application that helps network administrators rapidly deploy multiple cisco software licenses across their networks. When implementing eigrp unequal cost load balancing using the variance command, which two conditions must be met. Eigrp uses diffusing update algorithm dual to choose the best path from the source to the destination. Eigrp unequal cost load balancing configuration video6. May 11, 2011 eigrp unequalcost load balancing eigrp can also balance traffic across multiple routes that have different metricsthis is called unequalcost load balancing. The multiplier is a variance value, between 1 and 128, used for. Eigrp is a ciscoproprietary hybrid routing protocol, incorporating features of both distancevector.
The multiplier parameter for the variance command is a value from 1 to 128, used for load balancing. The site was designed to help you pass the ccna exam 200125, but it can also be used as a reference site for anything networking related. How to configure and verify eigrp stubs, eigrp load balancing and eigrp. Using routing capabilities is a must in todays evolving networks. Load balancing with eigrp all of our interior gateway protocols can perform equalpath load balancing on up to 4 routes by default. Understanding basics of eigrp routing protocol features of eigrp.
In this lab, well go over eigrp unequal cost load balancing theory, and then put that theory into action in a lab with live. In this lab i will explore equal and unequalcost loadbalancing for eigrp and will explain how eigrp calculates its metric values. Eigrp enhanced interior gateway routing protocol eigrp is a ciscoproprietary hybrid routing protocol, incorporating features of both distancevector and linkstate routing protocols. Learn how to change the reference bandwidth, the costs on ports as well as the maximum allowed equal cost paths that may be used in ospf. Eigrp uses the concept of the rid as a loopprevention mechanism to filter out a routers own routes. Like other linkstate routing protocols, eigrp uses eigrp hello packets to establish relationships with neighboring eigrp routers. In an enterprise environment, using eigrp enhanced interior gateway protocol is your best choice because eigrp is fast and agile. Convergence, bandwidth usage, subnetting, load balancing. Jun, 20 now lets configure unequalcost load balancing to make use of the link via e10.
Both eigrp for ipv4 and eigrp for ipv6 support unequal cost load balancing. Pdf on jul 1, 2016, hasanein hasan and others published. The protocol was designed by cisco systems as a proprietary protocol, available only on cisco routers. Eigrp equal and unequal cost load sharing eric leahy. To download cisco ccnp routing pdf study guide click here. A significant advantage of eigrp and igrp over other routing protocols is the support for unequalcost load balancing. By setting the variance to 10 we are telling the router to load balance over routes that have an fd of up to 10 times worse than the fd of the successor route. By default, eigrp supports equalcost load balancing over four links. Configuring eigrp maximum paths free ccna workbook.
In this way, eigrp provides both unequal cost path load balancing and intelligent load balancing. Configure and verify eigrp stubs, eigrp load balancing and eigrp neighbor relationship and authentication. Router used as a frame reay switch lab 25, eigrp authentication and. Enhanced interior gateway routing protocol eigrp enhanced interior gateway routing protocol. Eigrp supports up to 6 loop free paths with a metric lowers than the product of variance and the best metric. Functionality of eigrp was converted to an open standard in 20 and was published with informational.
Eigrp makes it easy for us the network engineers to make this happen. Some eigrp packets are sent as multicasts destination ip address 224. Enhanced interior gateway routing protocol eigrp are. Eigrp unequal path load balancing can result in routing loops d. How does unequal cost path load balancing variance work. A comparative study of igp and egp routing protocols, performance evaluation along load balancing and redundancy across different as. Is there any special reason why only eigrp supports this feature. Many of you have problems finding a comprehensive guide to load balancing for eigrp. When the router load balances over multiple paths using the routing table, the default load balancing behavior is perdestination load sharing. Eigrp enhanced interior gateway routing protocol is an enhanced distancevector protocol. Hello all, we are planning to do eigrp load balancing between three locations previously we have direct connection between location1 ppp via ddn line t1 128kbps and location2 we are using cisco 1721 with eigrp protocol redistribution of rip v2 now we. Eigrp introduced significant improvements to the igrp routing protocol including support for vlsm and cidr, guaranteed loop free routes, and faster convergence times. Download our free ultimate runbook and see how predictive analysis can help you. This guide from indeni details not only eigrp configuration but load balancing, routing.
The manual summarization is needed on a hub to advertise the default route to. Cisco ios software supports equal cost load sharing for a default of up to four paths for all routing protocols. You also must set the number of maximum pathswe are going to use when load balancing with eigrp. The metric of the route must be lower than the metric of. Load balancing has always been a trivial issuse for many cisco engineers. Pdf a comparative study of igp and egp routing protocols. Lab 2 1 eigrp configuration bandwidth and adjacencies. Known as eigrp stuck in active is a state which occurs if a router does not receive a reply to a query within the configured active time 3 min.
Enhanced interior gateway routing protocol wikipedia. Dual is used by eigrp to achieve fast loopfree convergence with little. Eigrp configuration, bandwidth and adjacencies chapter 2. Routing juniper security lan technologies layer 1 load balancing monitoring and management mpls. Eigrp, however, can also load balance over unequal cost links. It will connect through r2 and r3 to ip address 124. A path has to be a feasible successor route to be used in unequal load balancing.
Your top of the line datacenter switching platform nexus doesnt support your own fucking protocols eigrp one main benefit. Welcome to website, a free ccna tutorial site that closely follows the cisco ccna curriculum. By default, eigrp performs equal cost load balancing at least across four equal cost paths. Eigrp performs autosummarization by default, but this behavior can be disabled with the.
Now in order to qualify as a load balancing link,the link itself must qualify as a feasible successor first. Both spokes can see r1s loopback, but neither r2 nor r3 has an entry for the others loopback. You can view the eigrp topology and the route to 10. Before jumping in the ins and out lets run through a few things first when it comes to eigrp load sharing, also refereed to as load balancing sometimes. Eigrp unequal cost load balancing configuration video6 in hindi. To better understand the equalcost load balancing concept, consider the following example. Chapter 2 lab 22, eigrp load balancing topology objectives.
Pdf improvement of performance of eigrp network by using a. We can verify this by looking at the output of show ip protocols, it will tell us what the maximum path value is. The degree to which eigrp performs load balancing is controlled with the variance command. Now lets configure unequalcost load balancing to make use of the link via e10. Eigrp overview enhanced interior gateway routing protocol or eigrp is ciscos proprietary distance vector routing protocol that replaced the earlier igrp routing protocol. During the last decades people have become witnesses to the rapid expansion of data networks. Jun 06, 2014 recently, i was asked a question regarding traffic load balancing across several links and i was able to provide two options that i thought would work. Configure and verify equalcost load balancing with eigrp. How to test eigrp loadbalancing solutions experts exchange. Ccnp route lab manual with solutions config router. So i would need to mess with the metrics to influence the links to make. Feb 19, 2020 eigrp can also balance traffic across multiple routes that have different metrics, which is called unequalcost load balancing. Advantages of eigrp uses multicast instead of broadcast utilizes link bandwidth and delay eigrp metric igrp metric x 256 32 bit vs. It also supports unequal cost load balancing between routers.
Since the feasibility condition used by eigrp allows for selecting only loop free alternatives it is safe to enable uclb on eigrp routers provided that eigrp is the only routing protocol all alternate paths will never result in a routing loop. The route must be loopfree, a current feasible successor in the topology table. The route must be loop free, a current feasible successor in the topology table. How does unequal cost path load balancing variance work in. Discover how the cisco eigrp performs load sharing, or load balancing, over equal cost paths. Have you ever wondered why among all igps only eigrp supports unequalcost load balancing uclb. The route must be loop free, by meeting the feasibility condition. The eigrp is commonly the routing protocol of choice when using the network with no requirement for the cross vendor operation.
In this situation, eigrp sends two packets to eca and one packet to eba. Routes with equal feasible distance are installed by default in the. A simple tip out here is that ospf will do equal cost lad balancing by default so if you want to load. Eigrp has a maximum hopcount of 224, though the default maximum hopcount is set to 100. The degree to which eigrp performs load balancing is controlled by the variance multiplier router configuration command. But editing is not allowed and commercialization of. Aug 12, 2012 in this post i would like to explore unequal cost load balancing with eigrp and particularly how we configure eigrp in order to achieve load balancing. Download cisco ccnp routing pdf study guide snabay. As you can see from the routing table on r1 shown above that r1 is no longer load balancing traffic to 10. Sep 19, 2011 eigrp makes it easy for us the network engineers to make this happen. Load balancing in eigrp these videos are free to share and learn and upload in your personal blogs, computers and with your friends. Eigrp has low usage of network resources during normal operation.
The eigrp supports multiple routed protocols, including ipx, appletalk and ip. I will talk about the feasible distance, the metric weights, offsetlist, the different methods we can use to change traffic sharing among multiple unequal cost paths with eigrp and. Eigrp can also balance traffic across multiple routes that have different metrics, which is called unequalcost load balancing. Administrative distance 90 internal, when routers are connected in the same autonomous system, 170 external, when routers are connected in different autonomous system.
Explore methods to manipulate how many maximum paths are available to the router. So by default, equal path load balancing is onand can support up. Eigrp has 2 forms of load balancing equal and unequal, for equal to work there must be more than 1 route to the destination that is equal to the other route in terms of metrics k1k5 in the routing table, only 4 routes by default up to 32 with maximum paths can equally load balance at the same time, this would provide you with more resiliency redundancy and share the traffic over multiple. Fast reroute means we switch to another next hop, loop free alternate is an alternative path in the network that is loop free. By default, eigrp uses a default variance of 2 for load balancing. I have decided to create articles on those solutions. Lets start with the basic idea of equalcost loadbalancing eclb. The unequalcost loadbalancing with eigrp is subject to one aditional restriction, the best metric is selected fd and multiplied by the variance, so anything in that range will be used to load balance over. Ciscos enhanced interior gateway routing protocol eigrp. You can configure eigrp in all routers such as the cisco 2500 series and. In addition, interior gateway routing protocol igrp and eigrp also support unequal cost path load balancing. As with autosummarization, the router performing manual summarization will add the.
Successors and feasible successors when unequalcost load balancing is enabled with the. Enhanced interior gateway routing protocol eigrp is an advanced distancevector routing protocol that is used on a computer network for automating routing decisions and configuration. New ways of working, communicating and socializing have been accompanied by new terms such as bring your own device byod, the internet of things and. Even better it will share traffic in a proportional way, if you have a feasible successor that has a feasible distance which is 5 times worse than the successor then traffic will be shared in a 5. Eigrp adheres to the following hybrid characteristics. Pdf simulationbased comparative study of ospf and eigrp. Ccnp route chapter 2 lab 21, eigrp load balancing version 7. At the end of the previous eigrp tutorial, we noticed that only r1 has an entry for both loopbacks in its routing table. Eigrp puts up to four routes of equal cost in the routing table, which the router then load balances. Eigrp load balance with a variance 1, meaning that equal cost fd is needed in order to accomplish load balancing. If you are running ospf, dont try any method of load balancing. Eigrp overview eigrp enhanced interior gateway routing protocol is an advanced distance vector routing protocol.
Nov 22, 2006 hello all, we are planning to do eigrp load balancing between three locations previously we have direct connection between location1 ppp via ddn line t1 128kbps and location2 we are using cisco 1721 with eigrp protocol redistribution of rip v2 now we want to connect location1 to location2 and locat. Eigrp is supported in cisco ios software release 9. On r1, view the routing table and verify that r1 is loadbalancing to 10. Eigrp will form neighbor relationships with adjacent routers in the. The type of load balancing per packet or per destination depends on the type of switching being done in the router. It is sometimes referred to as a hybrid routing protocol because it has characteristics of both distancevector and linkstate routing protocols. Eigrp allows a maximum of four paths across for load balancing traffic b.
In this lab, well go over eigrp unequalcost load balancing theory, and then put that theory into action in a lab with live. Equalcost means that multiple routes must have the same metric to reach the destination, so that router can choose to load balance across equal cost links. Eigrp in cisco nxos does not support unequal cost load balancing. Dec, 2011 in this lab i will explore equal and unequalcost loadbalancing for eigrp and will explain how eigrp calculates its metric values. Eigrp loop free alternate lfa fast reroute frr is a feature that allows eigrp to switch to a backup path in less than 50 ms. Ccnp route lab manual with solutions chapter 1 lab 11, tci script reference and demonstration chapter 2 lab 21, eigrp configuration, bandwidth, and adjacencies lab 22, eigrp load balancing lab 23, eigrp summarization and default network advertisement lab 24, eigrp frame relay hubandspoke. Neither eigrp for ipv4 nor eigrp for ipv6 support unequal cost load balancing. Equal and unequal cost load balancing eigrp support equal and unequal cost load balancing equal cost load balancing is enabled by default. The metric of the route must be lower than the metric of the best route successor, multiplied by the variance configured on the router. Eigrp is a ciscoproprietary hybrid routing protocol that contains features of distancevector. How to convert pdf to word without software duration. Eigrp uses diffusing update algorithm dual to determine the best path among all feasible paths. There has never been a shortcut for a load balancing. Topology r1 is the router we will be doing our tests from.
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