Introduction

This lab is meant for the fifth grade students of the Radio Engineering and Сybernetics Department of Moscow Institute of Physics and Technology as well as for the third year students who would like to learn about the additional features of EIGRP on an extracurricular basis. It is implied that the students are already familiar with the basic operation principles of EIGRP and both protocol configuration syntaxes. All commands presented in this lab are for named mode, but the students should be able to perform the same configurations in the classic mode too, if applicable.

It is allowed to use third-party educational materials upon doing this lab.

Description

Addressing scheme for the serial links between the routers is as follows: 192.168.XY.X|Y/24 where X and Y are serial numbers of devices. For example, let's examine the link between routers R1 and R2. Router R1 interface is assigned 192.168.12.1/24 IP address, whilst the router R2 has 192.168.12.2/24. The right Ethernet segment features four networks where the users are located. EIGRP with the autonomous system #1 is used in the network.

The image below shows the L3 scheme of the network. Every network is located in its own VLAN; this is why the respective amount of sub-interfaces should be created on the routers R2 to R4.

Every section in this lab covers a wide range of EIGRP operation features without being limited to what the title says.

Network scheme

K-values

  1. Build the presented scheme using GNS3. Enable all interfaces and assign the IP-addresses to them. Use different encapsulation (PPP, HDLC, and Frame Relay) on all serial links.
  2. Add all physical interfaces and sub-interfaces to EIGRP. Use sho eigrp address-family ipv4 1 neighbors command to make sure that the neighbor relationship between them was formed.
  3. Make sure that router R1 has routes towards all four user networks through all of its three neighbors and that it performs balancing between the three paths with the same metrics. Remember the metrics value for, let's say, 192.168.0.0/24 network.
  4. Learn K-values using the following commands: sho ip protocols or sho eigrp protocols. By default, the weights are the following: K1=1, K2=0, K3=1, K4=0, K5=0 K6=0.
  5. Reconfigure the K-values on router R1in such a way that only the interface delay is considered upon the metric calculation.
  6. Make sure that router R1 lost the EIGRP neighbor relationship with all other three devices.
  7. Reconfigure the K-values the same way on three other routers.
  8. Make sure that the EIGRP neighbor relationship between them was re-established.
  9. Make sure that the metrics for 192.168.0.0/24 has changed.

RIB Scale

  1. Look at the output of sho eigrp address-family ipv4 1 topology | s 192.168.(0|1|2|3).0/24 command and make sure that the metrics of 192.168.0.0/24, 192.168.1.0/24, 192.168.2.0/24 , and 192.168.3.0/24 networks coincide and are the same irrespective of the path.
  2. Use sho ip ro ei | s 192.168.(0|1|2|3).0/24 command to make sure that the metrics of routes towards the specified networks in RIB is different from the one that was shown in the previous item. The difference is due to the usage of 64-bit metrics in the EIGRP named mode, whilst the value of the RIB metrics is 32-bit long.
  3. Use sho ip protocols or sho eigrp protocols command to make sure that EIGRP uses 64-bit metrics.
  4. A special kind of scaling factor, which is 128 by default, is used in order to convert the EIGRP metrics value into the RIB one. Find its value in the outputs of the following commands: sho ip protocols and sho eigrp protocols. Make sure that the calculation of metrics for networks located in the routing table is correct using integer division of the internal EIGRP metrics by the scaling factor.
  5. Use metric rib-scale 200 command to change the scaling factor value. Make sure that the metrics value in the routing table was changed.
  6. Delete the configuration command from the previous item. Make sure that the metrics in the routing table is now equal to its previous value.
  7. Note that it's possible to change the scaling factor not on all routers in the network.

Feasible successor

  1. Use sho eigrp address-family ipv4 1 topology | s 192.168.(0|1|2|3).0/24 command to review the information located in the topology table about the client networks. At this moment all three routes have the same metrics and balancing is performed over all three paths with the same metrics.
  2. Use delay interface command to change the delay values on all four routers in such a way so that they coincide with the values presented on the scheme above.
  3. Review the routing table on R1 and make sure that balancing for client networks is not performed any more and all the traffic is transferred only through router R2.
  4. Use sho eigrp address-family ipv4 1 topology command to review the topology table on router R1 and make sure that there are no routes towards client networks through routers R3 and R4.
  5. The routes towards clients networks through routers R3 and R4 have disappeared from the topology table because feasible condition is not met any more. Remember and write it down.
  6. Use sho eigrp address-family ipv4 1 topology all-links command to review the full topology table on router R1. Make sure that the routes toward client networks through routers R3 and R4 are not met feasible condition.
  7. Make up and change the delay values on the interfaces in such a way so that two paths appear in the topology table: one through successor and the other one through feasible successor. The metrics value for all three routes must be different.
  8. Make sure that there is still only one route for every client network in the routing table.

Unequal cost load balancing

  1. Use the corresponding commands on router R1 to make sure that after performing all tasks from the previous section correctly the topology table has two paths with different metrics for every client network and the routing table has only one best route.
  2. Use variance 128 command to change the multiplier that is used for choosing the routes that are placed into the routing table.
  3. Make sure that two routes for every client network appeared in the routing table.
  4. Change variance command in such a way so that the smallest possible multiplier, letting both routes make it into the routing table, is used.
  5. Explain in what way the selection of routes that are placed into the routing table is made.
  6. Change the delay value on the interfaces of routers in such a way so that feasible condition is met for all three routes towards client networks.
  7. Make sure that all three routes towards client networks (change the value of variance command if necessary) appeared in the routing table.
  8. Use sho ip protocols and sho eigrp protocols commands to learn what is the largest number of prefixes that one can place in the routing table.
  9. Use maximum-paths 2 command to limit the number of routes placed in RIB.
  10. Make sure that the routing table has only two routes toward every client network.
  11. Use maximum-paths command to increase the number of routes placed in the routing table in such a way so that all the routes successfully appear in RIB once more.
  12. Use traffic-share balanced command to choose one of the balancing modes. Explain the differences between the modes.
  13. Use one of the review commands to learn the ratio for traffic balancing for every user network.
  14. Use traffic-share min across-interfaces command to change the balancing mode. Learn what would be the traffic balancing ratio now.

Passive interfaces

  1. Use sho eigrp address-family ipv4 topology 192.168.0.0/24 command on router R1 to make sure that the topology table has all three paths towards the corresponding network.
  2. Use shutdown command on router R2 in the corresponding section of the routing protocol settings to disable EIGRP for the interface that is assigned 192.168.0.2 IP address.
  3. Use sho eigrp address-family ipv4 interfaces command on the same router to make sure that the corresponding interface doesn't participate in EIGRP any more.
  4. Use sho eigrp address-family ipv4 topology 192.168.0.0/24 command to make sure that router R2 doesn't announce routing information about 192.168.0.0/24 network toward router R1.
  5. Use redistribute connected command to make R2 announce information via EIGRP about the directly connected networks.
  6. Review the topology table on R1 for 192.168.0.0/24 prefix once more. Explain what you saw.
  7. Use passive-interface command on R3 in the corresponding section of the routing protocol settings to switch the interface that is assigned 192.168.0.3 IP-address to the passive mode.
  8. Use review commands on router R4 to make sure that R4 doesn't have EIGRP neighbors in 192.168.0.0/24 network.
  9. Use sho eigrp address-family ipv4 topology 192.168.0.0/24 command on R1 to make sure that the topology table still has three paths, two of which are internal.
  10. Use sho eigrp address-family ipv4 1 interfaces command on router R3. Make sure that there is no interface assigned 192.168.0.3 IP-address among EIGRP interfaces.
  11. Use sho ip protocols command on R3 to find out what interfaces operate in the EIGRP passive mode.
  12. Use sho ip ro ei 1 command on router R1 and find the metrics and administrative distance values for 192.168.0.0/24 prefix from the output of this command.
  13. Use distance eigrp 200 100 command on R1 to change the administrative distance values for internal and external EIGRP routes.
  14. Use sho ip protocols or sho eigrp protocols command to make sure that the changes have been added successfully.
  15. Re-establish the EIGRP neighbourship from R1 with all other routers.
  16. Review the routing table on R1 for 192.168.0.0/24 prefix once again. Please explain the changes that took place.
  17. Examine the topology table for 192.168.0.0/24 prefix on R1. Find and explain the changes.
  18. Delete distance eigrp 200 100 command from the EIGRP settings on router R1 and re-establish EIGRP neighbourship between all routers.
  19. Use sho ip protocols or sho eigrp protocols command to find out the default value that limits the diameter of the EIGRP network.
  20. Use sho eigrp address-family ipv4 topology 192.168.0.0/24 command on router R1 and examine its output to learn how far away (in terms of L3 hops) 192.168.0.0/24 network is located from this router upon usage of every of the three available paths.
  21. Use metric maximum-hops command on router R1 to increase the supported EIGRP network diameter.
  22. Use sho ip protocols or sho eigrp protocols command to make sure that the changes have been added successfully.
  23. Delete metric maximum-hops command that you had used earlier on router R1.
  24. Delete shutdown command on R2 in the module of EIGRP settings for the interface that's assigned 192.168.0.2 IP address. Also, disable announcing of the connected networks in EIGRP.
  25. Delete passive-interface command on router R3 in the section of EIGRP settings for the interface that's assigned 192.168.0.3 IP address.

Stub routers

  1. Create Loopback 0 interface with х.х.х.х/32 IP address, where x is the router number, on all routers and add it to EIGRP.
  2. Examine the topology table on router R1 for х.х.х.х/32 networks.
  3. Configure R2, R3, and R4 as stub routers with announcing of only the connected networks.
  4. Use sho ip protocols or sho eigrp protocols command on R2, R3, and R4 to make sure that the changes have been added successfully.
  5. Use sho eigrp address-family ipv4 neighbors detail command on R1 to review the detailed information about routers R2, R3, and R4.
  6. Examine the topology table on R1 for х.х.х.х/32 networks. Please explain the changes that took place.
  7. Create prefix list that allows the following prefixes on R2: 3.3.3.3/32 and 4.4.4.4/32.
  8. Create a route-map on router R2 that will allow what would be allowed by the prefix-list created in the previous item.
  9. Change eigrp stub command on R2 in such a way that not only the directly connected networks but also the ones that are allowed using the previously created route-map are included in the EIGRP announcements.
  10. Review the topology table on R1. Please explain the changes that took place.
  11. Use deb eigrp fsm command on R1 to enable the output of debugging data about EIGRP FSM events.
  12. Disable the sub-interface that is assigned 192.168.0.2 IP address on router R2.
  13. Examine the debugging messages shown in the console of R1.
  14. Use u all command on R1 to disable the output of debugging messages in the console.
  15. Enable the sub-interface that is assigned 192.168.0.2 IP address on R2.
  16. Configure traffic capturing on all L2 segments on the scheme using Wireshark.
  17. Disable Loopback 0 interface on router R2.
  18. Examine all QUERY and REPLY messages that the routers have been interchanging. Examine the distribution area of EIGRP QUERY messages.
  19. Disable all performing traffic captures.
  20. Enable Loopback 0 interface on R2.
  21. On routers R2, R3, and R4, delete setting that makes them perform functions of stub routers.
  22. Use sho eigrp address-family ipv4 interfaces detail command on R1 to examine default values of hello and hold intervals.
  23. On routers R1 and R2, specify the value of the hold interval as 10000 seconds for the interface that connects these devices.
  24. Use sho eigrp address-family ipv4 interfaces detail command to make sure that the changes have been made successfully.
  25. Create an extended access list that allows all traffic types except EIGRP on R2 and apply it for the incoming direction to the interface that interconnects R1 and R2.
  26. Make sure that R2 does not receive EIGRP HELLO packets from R1 any more.
  27. Perform capturing of all EIGRP messages on the link between R1 and R2 using Wireshark.
  28. Disable Loopback 0 interface on router R3.
  29. Use sho ei address-family ipv4 topology 3.3.3.3/32 command on R1 and learn in what state 3.3.3.3/32 prefix is being from the output of this command.
  30. Use sho eigrp address-family ipv4 topology active command to review all prefixes that are active.
  31. Delete the access list previously created on R2.
  32. Enable Loopback 0 interface on R3.
  33. Specify the default values for hold intervals on routers R1 and R2.
  34. Review EIGRP messages captured via Wireshark. Disable all captures that are being performed.

Route summarization

  1. Configure summarization for client routes to 192.168.0.0/22 prefix on R2 and R3.
  2. Examine the routing table and topology table on R1. Explain what you saw.
  3. Also, configure summarization for client routes to 192.168.0.0/22 prefix on R4.
  4. Examine the routing table and topology table for 192.168.0.0/22 prefix on R2. Explain what you saw.
  5. Use summary-metric 192.168.0.0/22 distance 10 command to change the value of the administrative distance for 192.168.0.0/22 prefix on R2.
  6. Use summary-metric 192.168.0.0/22 distance 255 command on R3.
  7. Examine the routing table and topology table on routers R1 and R3. Explain what you saw.
  8. Delete the commands that change the administrative distance on R2 and R3.
  9. Use show ip protocols command on routers to which the client networks are connected to learn what kind of route summarization is being performed.
  10. Create a prefix-list that allows 192.168.1.0/24 prefix on R4.
  11. Create a route-map on router R4 that will allow what would be allowed by the prefix-list created in the previous item.
  12. Delete the command that performs summarization of client prefixes on R4.
  13. Use summary-address 192.168.0.0/22 leak-map name command, where name is the name of the previously created route-map, on R4.
  14. Examine the routing table and topology table on R1. Explain what you saw.

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