Passive, active, and stuck in active sia passive routes are routes that have successor information passive route good active routes are routes that have lost their successors and no feasible successors are available. Eigrp packet is received from that neighbor long ago and far way, it needed to be a hello received, but now any eigrp packet will reset the timer since hellos are sent every five seconds on most networks, the hold time value in a show ip eigrp neighbors is normally between 10 and 15 resetting to hold. Show ip eigrp traffic shows no hellos sent or received and show ip eigrp says the process is running but no neighbor form. When a router enters the stuckinactive state, the neighbors from which the reply was expected are reinitialized, and the router goes active on all routes learned from those neighbors. Id like to tell you a little bit more about the eigrp query process and the stuckinactive problem. In fact, its so common that cisco has an acronym for it.
Where eigrp scaling problems usually become evident is with stuckinactive sia conditions, in which responses to queries are not heard within a certain time, causing neighbors to be incorrectly. The router is actively looking for alternative paths active route bad stuck in active means the neighbor still. Enhanced interior gateway routing protocol eigrp is an advanced distance vector routing protocol based on the principles of the interior gateway routing protocol igrp. By default, eigrp uses only up to 50% of an interfaces bandwidth for eigrp information, which prevents the eigrp process from overutilizing a link and not allowing enough bandwidth for the routing of normal traffic. Docs txtpdf draftsavageeigrp tracker diff1 diff2 ipr errata.
Once the eigrp neighbor relationships form, dual will begin sending a series of queries and responses, and these responses are used to build the eigrp topology table. When the sia occurs, the router clears the neighbour that did not reply to the query. This process puts the route in what is termed active state. Determining activestuck in active routes with show ip eigrp topology active. A route goes from active state to passive state when a router receives responses from all of its neighbors and the diffusing computation is complete. Cisco systems, inc changing the way we work, live, play, and learn, and. In a poorly designed network, eigrp queries can be the downfall of the network as an eigrp route can become sia stuck in active. Some query or reply packets are lost between the routers.
Eigrp network design solutions uses case studies and realworld configuration examples to help you gain an indepth understanding of the issues involved in designing, deploying, and managing eigrpbased networks. Earlier ios versions treated changes in eigrp summary address configuration configured with the ip summaryaddress eigrp interface configuration command very disruptively. Eigrp queries and stuckinactive with eigrp, if a router loses a route and it does not have an fs in the topology table, it sends out queries to neighboring routers to recompute a new route. Ethanalyzer shows neighbors sending hellos but not hellos being sent from the nexus 5k or nexus 6k itself. Eigrp is able to automatically create summary routes. An autonomous system number that is the same on all network routers must be entered. While troubleshooting an eigrp routing problem you notice that one of the routers have generated a large number of sia messages. Building scalable cisco internetworks it solutions. The router eigrp command entered in global configuration mode with autonomoussystemnumber argument creates an eigrp routing instance.
Both are owned by cisco and operate only on their devices. Troubleshooting ip routing protocols ccie professional. While eigrp does not have the stub area options that ospf does, eigrp does allow a router to be configured as stub. Can anyone please explain to me what this is and how it would happen, and what to do to rectify it.
This lesson explains how it works and what discontigious networks are. An eigrp reply packet was not received from one or more neighbors within the timeframe of 180 seconds. Id like to tell you a little bit more about the eigrp query process and the stuck inactive problem. Internetdraft eigrp february 20 while a router has a route in active state, it records the new metric information but does not make any routing decisions until it goes back to passive state. Interaction between the hold timer and the sia timer 5. Serving as both a complete reference and a practical handbook, eigrp for ip is an essential resource for network professionals charged with maintaining an efficient, smoothly functioning network. Provision of insufficient bandwidth for the eigrp process. Case studies and configuration examples help readers put the concepts into practice. An eigrp neighbour or neighbours have not replied to the query for that route. How to configure eigrp on cisco routers with example. A destination that has remained in the active state in excess of a predefined time period at the local router cisco implements this as 3 minutes. When a router enters the stuckinactive state, the neighbors from which. Eigrp is a ciscoproprietary routing protocol that is based on igrp. This is commonly done with a hubandspoke configuration where the spoke routers do not have the resources to keep a full routing table.
If a query response is not received back from a router within the allotted time sia timer. Essentially, sia occurs when an eigrp router doesnt receive a query reply sent to its neighbor after three minutes. When eigrp returns a stuck in active sia message, it means that it has not received a reply to a query. When a route goes active, eigrp sends queries to all neighbors. Methodology for troubleshooting the stuck in active problem. Deploying eigrp on a largescale threelayer hierarchical network 75. Enhanced interior gateway routing protocol eigrp is an advanced dynamic routing protocol that is used for routing decisions and configuration on the routers. Changes in eigrp summary address are no longer disruptive. What is the enhanced interior gateway routing protocol. A destination that has remained in the active state in excess of a. Sia situations can become very ugly and cause some serious downtime. Quiz 106 foundation topics 108 failure detection and timers 108 convergence 109 stuck in active 112 route summarization 1 interfacespecific summarization 114 summary discard routes 116 summarization metrics 116 automatic summarization 117 wan considerations 118 eigrp stub router 118. The specific number chosen does not matter, as long as a value between 1 and 65535 is entered and the entry is.
Eigrp stuck in active sia and stub network configuration. When a eigrp connection is in the active state it means the adjacency is not formed and it is currently calculating best paths etc. For a particular destination, a neighboring router that meets the feasibility condition and, at the same time, provides the least cost path. Eigrp route filtering with distributelists standard acls eigrp route filtering with. While the delay wasnt more than 5 seconds, packet loss could cause retransmissions. Activepdf is the leading global provider of serverside pdf automation and digital transformation tools that enable the ability to create, convert, modify. Cisco public objectives describe the background and history of enhanced interior gateway routing protocol eigrp. After some time, we see that r5 kills the neighborship to r6 and declares an sia state. Eigrp is a successor to the interior gateway routing protocol igrp. It is the first step in configuring eigrp on a router as done here on r1. The pdf files and any printed representation for this material are the property of cisco. X hs r1 sends a query pa ckage to all these neighbors except its old successor. Eigrp troubleshooting lab learning objectives upon completion of this lab, you will be able to. Since a response was not received the eigrp neighborship will be torn down in some time and reestablished using normal procedure.
Eigrp is a routing protocol based on distance vector technology. Ciscos enhanced interior gateway routing protocol eigrp. The neighboring router starts receiving route updates from this router. It details proper designs that can be used to build large and scalable eigrpbased networks, and documents possible ways each eigrp. What are two possible causes for eigrp stuckinactive routes. Eigrp is not advertising routes to neighbors when the network administrators think that it should. Eigrp paced the delivery of its messages to avoid congestion. What does the neighbor statement in the eigrp configuration section do. Eigrp routes are denoted in the routing table with a d, which stands for dual diffusing update algorithm, which is the routing algorithm used by eigrp. Well take a look at this query process and also what sia stuck in active is and how to deal with it. A route is considered passive when a router is not recomputing a new route.
Protocol eigrp, a routing protocol designed and developed by cisco systems, inc. This will be helpful to understand why we use the eigrp stub feature. Eigrp sends a query when a route is lost and another feasible route does not exist in the topology table. Ccnp routing and switching route 300101 complete video. Eigrp stuck in active fingerinthenet for english guy. Chapter 3 advanced eigrp 106 do i know this already.
Eigrp is activated on a router by entering configuration mode and the eigrp command. Eigrp network design solutions provides readers with indepth knowledge of eigrp, the cisco routing protocol that runs many large enterprise and service provider networks. Alvaro retana, a technical leader in cisco systems core ip engineering. All eigrp routers in an as must confirm receipt of route update and the route is held in active state until its confirmed.
This document offers customized analysis of your cisco device. C connected, s static, i igrp, r rip, m mobile, b bgp. If youve completed lab 102 configuring mutual ospf and rip redistribution and lab 103 configuring mutual ospf and eigrp redistribution then you should be no stranger to mutual route redistribution if you did not complete the previous labs then to summarize mutual route redistribution up in a pretty little nut shell. Examine the basic eigrp configuration commands and identify their purposes. There is such thing as stuck in active, whereby the router has no received the relevant responses in time. Erase the startup configuration and reload a router to the default state. Bestselling author, expert instructor, and double ccie. Eigrp supports cidr and vlsm, allowing network designers to maximize address space. Describe the uses of additional configuration commands in eigrp. Eigrp was developed by cisco systems as a proprietary protocol, which can be used only on cisco routers but in 20 partial functionality of eigrp was converted to an open standard. Configuring mutual eigrp and rip redistribution free.
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