CCNA EIGRP LAB Question
Question
After adding R3 router, no routing updates are being exchanged between R3 and the new location. All other inter connectivity and Internet access for the existing locations of the company are working properly.
The task is to identify the fault(s) and correct the router configuration to provide full connectivity between the routers.
Access to the router CLI can be gained by clicking on the appropriate host. All passwords on all routers are cisco.
IP addresses are listed in the chart below.
| R1 Fa0/0: 192.168.77.33 S1/0: 198.0.18.6 S0/1: 192.168.60.25 S0/0: 192.168.36.13 |
R2 Fa0/0: 192.168.60.97 Fa0/1: 192.168.60.113 S0/0: 192.168.36.14 |
| R3 Fa0/0: 192.168.77.34 Fa0/1: 192.168.60.65 Fa1/0: 192.168.60.81 |
R4 Fa0/0: 192.168.60.129 Fa0/1: 192.168.60.145 S0/1: 192.168.60.26 |
Answer and explanation
(Note: If you are not sure how EIGRP works, please read my EIGRP tutorial: http://www.9tut.com/eigrp-routing-protocol-tutorial. Note: You can download this sim to practice here: http://www.9tut.com/download/9tut.com_CCNA_EIGRP_sim_question.zip)
We should check the configuration of the new added router first because it does not function properly while others work well. From the command line interface of R3 router, enter the show running-config command
From the output above, we know that this router was wrongly configured with an autonomous number (AS) of 22. When the AS numbers among routers are mismatched, no adjacency is formed.
(You should check the AS numbers on other routers for sure)
To solve this problem, we simply re-configure router R3 with the following commands:
R3>enable (you have to enter cisco as its password here)
R3#configure terminal
R3(config)#no router eigrp 22
R3(config)#router eigrp 212
R3(config-router)#network 192.168.60.0
R3(config-router)#network 192.168.77.0
R3(config-router)#no auto-summary
R3(config-router)#end
R3#copy running-config startup-config
Check R1 router with the show running-config command:
Notice that it is missing a definition to the network R3. Therefore we have to add it so that it can recognize R3 router
R1>enable (you have to enter cisco as its password here)
R1#configure terminal
R1(config)#router eigrp 212
R1(config-router)#network 192.168.77.0
R1(config-router)#end
R1#copy running-config startup-config
Now the whole network will work well. You should check again with ping command from router R3 to other routers!
Modifications:
Maybe in this EIGRP Sim you will see the “passive-interface …” command somewhere in R1 configuration. If the link between R1 to R2; or R1 to R3; or R1 to R4) routers has the “passive interface” then we have to remove it with the “no passive-interface …” command because it prevents EIGRP update from being sent on that interface. But if the “passive interface” is applied to the link between R1 and ISP router like this:
R1:
!
router eigrp 212
passive-interface s1/0
!
then we just leave it. Don’t use the “no passive-interface s1/0″ on R1 because the link between R1 & ISP doesn’t need EIGRP to run on it. A static route from R1 to ISP & “ip default-network” command in R1 are correct so that all the routers (R1, R2, R3, R4) can access the Internet.
(Note: The “ip default-network” command in R1 will advertise the static route of R1 (to go to the Internet) to other routers (R2,R3,R4) so that they can access the Internet too). In the exam you will see these lines in R1 configuration:
!
ip default-network 198.0.18.0
ip route 0.0.0.0 0.0.0.0 198.0.18.5
!
If you want to learn more about “ip default-network” command please read: http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094374.shtml
I read recent comments and realized that you will see the “passive-interface” in the link between R1 & ISP router so just leave it.
Note: Also some readers confuse about if we should use the wildcard masks on the “network” statements under EIGRP process or not. For example should we use:
router eigrp 212
network 192.168.77.0 0.0.0.3
The answer is: we can use wildcard masks or not, it does not matter. Not having a wildcard mask does not make the routes conflicting. The “network …” command in EIGRP (and OSPF, RIP) does not means “advertise this network” but means “If I has interface(s) belongs to this network please turn on EIGRP on that interface. Therefore when you don’t use wildcard mask EIGRP will turn on EIGRP on all interfaces that belongs to the network you specify in the “network …” command.
You should only use wildcard mask on EIGRP if you have 2 or more interfaces that belong to the same major networks but you don’t want to run EIGRP on all of them. For example if your router has 2 interfaces whose IP addresses are 192.168.30.1/28 and 192.168.30.17/28 but you only want to run EIGRP on the first interface, you can type “network 192.168.30.0 0.0.0.15″ under EIGRP process.
Other lab-sims on this site:
CCNA Configuration SIM Question (RIPv2 SIM)
i forget my name sory!!
Alhamdulillah
Today I have clear 200 120 with 90% marks
There was same EIGRP with little changes.
THNXXXX 9tut
Best of luck guys
@George thank you for replying
@uni
what about passive interface??
can any one explain about passive interface which comes in eigrp lab how to check or configure or remove this interface?? as my exam is on friday 30 may..
@Talha check this link will help.
http://www.examtut.com/2013/08/ccna-eigrp-simulation.html
any questions just drop by and for sure i will get back to you.
By the way I am sitting for my exam on 31st saturday!.. do let me know how was your experience.
Good Luck!
everyone is getting a extra network in the main router i guess….is it necessary to remove it?
what is the need to remove it?
our main aim is to make all routers connect to each other through eigrp right?
i dont think u need to remove any network in the main router.. after applying the proper configuration and fixing the flaws. network works smooth… only the passive-interface… for the ones who have doubts about this command.. if you have made the changes as shown here.. change de AS to 212… add the network of R3 in R1… you should try putting passive-interface command in one of the serials of the routers (R1,R2,R3.)..and see what happens ;)… you will notice that the adjyances to the router’s serial which passive interface was applied will go down… this means… no updates are being sent by that router through the serial interface… and now… try taking off the command (R3(config-if)# no passive-interface) .. and then you will notice that adjancy to that router will be up again….
This is what you have to do (taking the passive interface) if you notice in your exam that communication is not working to a specific router…
im sorry i made a huge mistake on how and where to type the passive interface command.
this is where and how(i took it from my pkt sim)
R2#config t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#router eig
R2(config)#router eigrp 212
R2(config-router)#passi
R2(config-router)#passive-interface s0/0
R2(config-router)#
%DUAL-5-NBRCHANGE: IP-EIGRP 212: Neighbor 192.168.36.13 (Serial0/0) is down: holding time expired
Notice the msg from EIGRP .. it lost the neighbor.. thus it went down… and now… will take off the passive interface command:
R2(config-router)#no passive-interface s0/0
R2(config-router)#
%DUAL-5-NBRCHANGE: IP-EIGRP 212: Neighbor 192.168.36.13 (Serial0/0) is up: new adjacency
Notice msg from EIGRP… neighbor came up again
hope it helps and again.. sorry for my previous explanation
@sergio thanks a lot for the explanation…really appreciate it..
i had another doubt…is it necessary to ping the isp?
and to do that we need to create any static routes and default network command..?
this is mentioned in http://www.examtut.com/2013/08/ccna-eigrp-simulation.html
really confused after reading it in examtut site….if anyone can explain..thanks
https://www.youtube.com/watch?v=J28UBCPWK04
This was on my exam today.
Modifications: AS number and network between R1 and R3.
@avinash
I did some testing in regads the ip default network and the ip route static…
ok here is what i found and im gonna try to be as clear as i can:
In THIS EXACT PKT SIM you dont need to add the ip default network command and the ip route static command… why? because if you check the router R1.. there is a route to the ISP learned throught EIGRP command (the ip learned is 198.18.0.6) OK … this is for the simulation… but what happens if in the examn you dont have communication with the ISP??
IF in the examn tells u that no other router have communication to the ISP, it’sbecause there no route to the ISP configuretad through RI…
So… this were my testing on the PKT SIM:
FIRST AS MENTIONED BEFORE.. R1 in PKT SIM has a route to ISP learned through ISP (this is how the sim comes by default)… i took down the eigrp route to the ISP interface:
R1(config)#router eigrp 212
R1(config-router)#no net
R1(config-router)#no network 198.0.18.6
After taking this… i try to ping the ISP router from any other router making sure there was no communication anymore. Doing this allows me to check the other commands and make testing.
SECOND… adding the ip default network command on R1 as shown below:
R1(config)#ip default-network 198.0.18.0
At this point… check again ping from any router to the router ISP.. with no success!!!
THIRD
ADD the static route in R1 to the ip address 198.0.19.15 (which is the ip on the interfaze of the ISP) as shown:
R1(config)#ip route 0.0.0.0 0.0.0.0 198.18.0.5
At this point.. still any otherthat is no R1 router cannot ping ISP so…
FOURTH
we need to redistribute the static route of R1 to the other routers as shown below:
R1(config-router)#redistribute static
OK… now take a moment for this… AT THIS POINT.. you are now able to ping ISP router from ANY ROUTER thus.. your network is fully converged and working smooth…
FINAL TEST
I wanted to know if we really needed the first command, the ip default network command…
soooo.. i took it down from R1 configuration… as shown below:
R1(config-router)#no ip default-network 198.0.18.0
and… TADA!!!!… even though i took down command ip default network… THE NETWORK KEEPS WORKING PROPERLY WITHOUT THE COMMAND
CONCLUSION
As per my testing on this specific PKT SIM.. the IP DEFAULT NETWORK command is no needed for communication with the ISP.. you only need the static route from R1 to ISP and apply the redistribude static command on R1 for the network to fully converge
IN THE REAL EXAM, IF YOU SEE THAT STILL YOUR NETWORK DOESNT WORK.. TRY ADDING THE IP DEFAULT NETWORK… I DONT KNOW… PERHAPS IN THE EXAM YOU REALLY NEED IT… BASED ON THE COMMENTS FROM OTHER PEOPLE… THIS WAS ONLY MY TESTING ON THE PKT SIM.
ANNNNNNDDD.. PLEASE IF I AM WRON PLEASE PLASE PLEASE CORRECT MEEEE!!!!! :)
@avinash
i hope you see my post before your exam… mine is tomorrow May 30th… at 9:30am… and to be honest i hadnt checked what you mentioned about the ip default network command and static… soo.. basically your comment made me investigate and… testing on my PKT SIM.. so if this problem comes in simulaiton i will be prepared thanks to u :D hahahahaha
Cheers!.. see you on the other side!
@sergio Thanks for such a detailed analysis and clear explanation..
Trust me your awesome..
All the very best to you for the test….Im confident you will clear it with ease and perfect score.
Please share your experience after your test…cheers!!!
@sergio another thing as 9tut site clearly mentions that there is no need to ping the ISP…just should be able to get the connectivity between three routers i,e R1,R2,R3…
I CAME TO KNOW THIS WHEN I READ THE TUTORIAL ONCE AGAIN….so dont panic if your not able to ping the ISP…
WISH YOU ALL THE BEST
Passes yesterday, labs were acl1 and acl2, and eigrp.
Pass Today with 958 marks..no passive interface but lab is slightly different …. u hve to advertise network to all hosts.
@wasif the experince was gud
ACL with slide modification allow HOST B to use web server to access finance server deny all other hosts ips change..
Thanks 9tut..
@Talha
Good one!
I am sitting for my exam in next 12 hours.
@Talha
What do you mean by saying: “u hve to advertise network to all hosts” ?
Passed my CCNA 200-120 today with a score of 1000/1000 thanks to 9tut and examtut. everything is on 9tut.. if any one need any thing or the dumps i used than email me on faizan_jehangir88@hotmail.co.uk and i will email them to you for free. also go through every single question on 9 tut. the labs are ACL 1 & 2 and EIGRP with the as number 22. any questions then you can ask me by emailing me .
@9tut is it necessary to remove the extra network in the eigrp sim?
please reply as soon as possible…test in 2 days
@avinash: If you see strang network that is unused, you should remove it.
@9tut Thankyou and you guys rock ! ! !
Hello Everyone,
I’m writing CCNA 200-101 next week. Can anyone please send me the latest dumps to my mail id krischplack@aol.com ?
please send latest dumps to andrew.mccoy37@gmail.com exam on 6/10 thank you so much
Hi, can anyone please send me the latest dumps to bennyc79@gmail.com?
Hello everyone. I have an interesting question
my question concerning EIGRP lab is that when you’re advertising the routes I saw in the explanation on 9tut that they didn’t give the wildcard mask; they leave the full network so eigrp process decides what to do when forming adjencyes on interfaces. Is that correct ? I mean you can see in the running configuration the mask of each network by looking at the interface configuration, so you can easily find wildcard mask.
It would be wrong if i’m advertising network with the given wildcard ? I mean my interest is that if the simulator will grade it or not.
Thank you 9tut.
Between the Cisco library and the labs and theory here I passed my exam to day.
Awesome
Passed yesterday , scored 986. Labs were eigrp ACL1 and 2 with 2 midification, all questions from 9tut.
@9tut admin please reply is it necessary to remove extra network in main router
@help it is necessary to remove if you see a strange network….i had the same doubt..admin replied me regarding this
@9tut you are telling to remove the strange network but how will we know that?
i mean the the network we are trying to remove may be the ip to get to isp in R1 router
please reply asap my test on tue
Dear All, Help, Please could you sent me a copy of your VCE at allcertif@yahoo.com I badly need it. Thanks
or just the crack.
@help: if you see a network statement that does not cover any IP addresses of that router then you can remove it. But don’t remove the network statement that points to the IP to get to ISP on R1 router. We need that network in EIGRP so that R1 can advertise it to other routers. That means if on R1 you see the network 198.0.18.0 then don’t remove it.
thanks 9tut got it now perfect!!!
awesome
any one can send me the vce file to my mail deepaks.dav94@yahoo.com i need it..
Max pls what is the modification
Does anyone know how the simulations are graded? if you miss something or make 1 little error , does that mean the entire question is marked off wrong? or do you get partial credit?
Wow! reading everyone’s comment really does gets me excited!! I’v been preparing for the CCNA since January, it is now June and I can’t wait to take it,! right now I’m only waiting for the voucher reply, after that I enrolled into a testing center and done!
The SIMS are really the same as a couple of months ago ?
@9tut. why use ip route 0.0.0.0 0.0.0.0 198.0.18.5 <—– instead of 198.0.18.7?
cleared CCNA with the score of 1000/1000, it was so easy
anyone need dumps or other helping material email me at elegance_96@live.co.uk
Hi all and thanks for the explanantions,,, very helpful. Am I correct in saying that there is a voucher floating around for money off your ccna exam?? would appreciate any details.
Hi, Colonel A4tech
You can’t use 198.0.18.7 because it is a broadcast address from the net. 198.0.18.4/30.
Since you have a point-to-point conection and from the chart you can see that the ip address of the interface S 1/0 on R1 is 198.0.18.6, the next hop address on the ISP must be 198.0.18.5.
i passed my exam and i have got 986/100 score. The exam was too easy labs were ACL1, ACL2, and EIGRP with some modification
thanks 9tut
The EIGRP sim is awesome for practice. Thank you admin.
Passed today with 1000.
Simulation was EIGRP with network statement missing and AS number incorrect.
Edge router to ISP was already configured for Default network and Static route to ISP. EIGRP was also defined for the network of ISP.. so no need to do anything except configuring EIGRP correctly in 2 routers.
Serial interface towards ISP in edge router was with passive interface command, but still, worked without disabling that. Serial interface was disabled so couldnot even go into the interface.. all the dumps are 100% valid. thanks all.