EIGRP Troubleshooting Sim
Question
The topology below is running EIGRP. You are required to troubleshoot and resolve the EIGRP issues between the various routers. Use the appropriate show commands to troubleshoot the issues.
Instead of posting the output of “show run” commands we post here the commands entered on each router to reduce some useless lines. Also you can try solving questions by yourself before reading the answers.
R1: int lo0 ip address 10.1.1.1 255.255.255.255 int e0/0 ip address 192.168.16.1 255.255.255.0 int s1/1 ip address 192.168.13.1 255.255.255.0 int s1/3 ip address 192.168.12.1 255.255.255.0 ! router eigrp 1 network 10.1.1.1 0.0.0.0 network 192.168.12.0 network 192.168.13.0 network 192.168.16.0 |
R2: int lo0 ip address 10.2.2.2 255.255.255.255 int e0/0 ip address 192.168.123.2 255.255.255.0 int s2/1 ip address 192.168.12.2 255.255.255.0 ! router eigrp 1 network 10.2.2.2 0.0.0.0 network 192.168.12.0 network 192.168.123.0 |
R3: int lo0 ip address 10.3.3.3 255.255.255.255 int e0/0 ip address 192.168.123.3 255.255.255.0 int s2/1 ip address 192.168.13.3 255.255.255.0 ! router eigrp 1 network 10.3.3.3 0.0.0.0 network 192.168.13.0 network 192.168.123.0 |
R4: int lo0 ip address 10.4.4.4 255.255.255.255 int lo1 ip address 10.4.4.5 255.255.255.255 int lo2 ip address 10.4.4.6 255.255.255.255 int e0/0 ip address 192.168.123.4 255.255.255.0 ! router eigrp 1 network 192.168.123.0 |
R5: int lo0 ip address 10.5.5.5 255.255.255.255 int lo1 ip address 10.5.5.55 255.255.255.255 int e0/0 ip address 192.168.123.5 255.255.255.0 ! router eigrp 1 network 10.5.5.5 0.0.0.0 network 10.10.10.0 0.0.0.255 network 192.168.123.0 |
R6: int lo0 ip address 10.6.6.6 255.255.255.255 int e0/0 ip address 192.168.16.6 255.255.255.0 ! router eigrp 1 network 10.6.6.6 0.0.0.0 network 192.168.16.0 metric weights 0 0 0 1 1 1 |
Note: In the exam, this sim uses IOS version 15 so “no auto-summary” is the default setting of EIGRP and it is hidden. You don’t have to type it.
You can download the pkt file to practice here: https://www.9tut.com/download/9tut.com_CCNA_EIGRP_Troubleshooting_Sim.zip
Question 1
Explanation
We can see R4 is missing the “network 10.4.4.4 0.0.0.0”, “network 10.4.4.5 0.0.0.0” and “network 10.4.4.6 0.0.0.0” statements so R5 cannot learn them.
Question 2
Explanation
For this question we have to check the routing table of R1 to find out the answer. Use the “show ip route” command on R1 we will get something like this:
The loopback0 interface of R5: 10.5.5.5 are advertised via both 192.168.12.2 and 192.168.13.3 so we can conclude traffic from R1 to R5 is equally load-balanced over R2 and R3.
Note: Another loopback interface of R5 10.5.5.55 is not advertised so it is not shown in the routing table of R1 above.
Question 3
Explanation
Check the configuration of R6 carefully and we can see the “metric weights” is configured like this:
R6: router eigrp 1 network 10.6.6.6 0.0.0.0 network 192.168.16.0 metric weights 0 0 0 1 1 1 |
Then you should check if R1 has the same “metric weights” or not. If not then the answer should be “K values are mismatched”.
For your information, EIGRP K values are the scale numbers that EIGRP uses in metric calculation . Mismatched K values can prevent neighbor relationships from being established. The syntax of “metric weights” command is:
metric weights tos k1 k2 k3 k4 k5 (with tos is the type of service and must always be zero)
Question 4
Explanation
Check the configuration of R5 with the “show running-config” command:
R5 router eigrp 1 network 10.5.5.5 0.0.0.0 network 10.10.10.0 0.0.0.255 network 192.168.123.0 ! |
We see that R5 does not advertise its loopback 0 (10.5.5.55) to EIGRP therefore a ping to this IP address will not be successful because R1 does not know how to send packet to R5.