EIGRP Stub Sim
Question
By increasing the first distant office, JS manufactures has extended their business. They configured the remote office router (R3) from which they can reach all Corporate subnets. In order to raise network stableness and lower the memory usage and broadband utilization to R3, JS manufactures makes use of route summarization together with the EIGRP Stub Routing feature. Another network engineer is responsible for the implementing of this solution. However, in the process of configuring EIGRP stub routing connectivity with the remote network devices off of R3 has been missing.
Presently JS has configured EIGRP on all routers in the network R2, R3, and R4. Your duty is to find and solve the connectivity failure problem with the remote office router R3. You should then configure route summarization only to the distant office router R3 to complete the task after the problem has been solved.
The success of pings from R4 to the R3 LAN interface proves that the fault has been corrected and the R3 IP routing table only contains two 10.0.0.0 subnets.
Answer and Explanation:
First we have to figure out why R3 and R4 can not communicate with each other. Use the show running-config command on router R3
Notice that R3 is configured as a stub receive-only router. The receive-only keyword will restrict the router from sharing any of its routes with any other router in that EIGRP autonomous system. This keyword will also prevent any type of route from being sent.
Therefore we will remove this command and replace it with the eigrp stub command:
R3#configure terminal
R3(config)#router eigrp 123
R3(config-router)#no eigrp stub receive-only
R3(config-router)#eigrp stub
R3(config-router)#end
Now R3 will send updates containing its connected and summary routes to other routers. Notice that the eigrp stub command equals to the eigrp stub connected summary because the connected and summary options are enabled by default.
Next we will configure router R3 so that it has only 2 subnets of 10.0.0.0 network. Use the show ip route command on R3 to view its routing table
R3#show ip route
Because we want the routing table of R3 only have 2 subnets so we have to summary sub-networks at the interface which is connected with R3, the s0/0 interface of R4.
There is one interesting thing about the output of the show ip route shown above: the 10.2.3.0/24, which is a directly connected network of R3. We can’t get rid of it in the routing table no matter what technique we use to summary the networks. Therefore, to make the routing table of R3 has only 2 subnets we have to summary other subnets into one subnet.
In the output if we don’t see the summary line (like 10.0.0.0/8 is a summary…) then we should use the command ip summary-address eigrp 123 10.2.0.0 255.255.0.0 so that all the ping can work well.
In conclusion, we will use the ip summary-address eigrp 123 10.2.0.0 255.255.0.0 at the interface s0/0 of R4 to summary.
R4>enable
R4#configure terminal
R4(config)#interface s0/0
R4(config-if)#ip summary-address eigrp 123 10.2.0.0 255.255.0.0
Now we jump back to R3 and use the show ip route command to verify the effect, the output is shown below:
(But please notice that the ip addresses and the subnet masks in your real exam might be different so you might use different ones to solve this question)
But in your real exam, if you see the line “10.0.0.0/8 is a summary,….Null0″ then you need to summary using the network 10.0.0.0/8 with the command “ip summary-address eigrp 123 10.0.0.0 255.0.0.0″ . This configuration is less optimize than the first but it summaries into 2 subnets as the question requires (maybe you will not see this case, don’t worry!).
The command “copy running-config startup-config” will not work so try using this command; just skip if it doesn’t work.
Other lab-sims on this site:
EIGRP Simlet
Policy Based Routing Sim
are you know V200?
i am know V200
pls does anyone know V200
Good News !!!
I have a updated dump contact me for it
kellysmith114@gmail.com
hi all
i cleared my route exam today. The Labs were – EIGRP – OSPF Redistribution Sim – Policy Based Routing Sim – IPv6 OSPF Virtual Link Sim – OSPF Sim
I Passed yesterday with score 965 , thanks guys and digitaltut :) all labs from here
http://www.4shared.com/file/MNxMccev/GNS3_642-902_Test_Sims.html
all labs from digitaltut.com in GNS3 format with IOS. Its not my work, i am just sharing
For the summary address on R4 why use the whole 10.2.0.0 network range?? why not use summary address 10.2.0.0 255.255.240.0 which covers 10.2.0.0-10.2.15.254?? this also leaves two subnet in the routing table of R3
Pls can anyone send me a copy of the latest CCNP Route dumps to my email: onecutesoul@hotmail.com
I will really appreciate it. Am kinda confused and dont knw how to get it at the moment.
just passed with 976. tnx digitaltut and all
@gillman:
Sham
February 5th, 2011
@ Swetha
If you use mask 255.255.0.0 you are advertising the whole class B block which is not wrong but not the most optimized summary, because that way R4 will advertises 10.2.0.0 – 10.2.255.0 although it only knows about 10.2.2.0-10.2.9.0 networks.
But if you use 255.255.240.0 mask. R4 will advertise only 10.2.0.0 – 10.2.15.0 networks only. Which is more specific than the previous case.That is the only difference.
In both cases, the routing table will have 2 subnets, so no harm done and both methods will follow the required criteria.
But personally I use 255.255.240.0 because that’s the best practice.
Hope this helps.
@All
When summarizing the networks 10.2.2.0 – 10.2.9.0 in R3 routing table I came with the summary 10.2.2.0/20. Is it wrong? and how the summary address 10.2.0.0 255.255.0.0 was obtained in the shown solution.
Can anyone explain it more for me?
Thanks
@ mohammad
if you put on s 0/0 your proposed summary address, you will also have the same output as the sim is requiring but if you look on the routing table you will get this output..
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.1.0 is directly connected, FastEthernet0/0
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
D 10.2.0.0/20 [90/2195456] via 10.2.3.4, 00:00:07, Serial0/0
C 10.2.3.0/24 is directly connected, Serial0/0
As you see, your summary address did not appeared because the right summary address is 10.2.0.0/20, it is from 10.2.0.0-10.2.15.0. In other words, you put an address within the range.
@agent_07
Thank you for ur reply.
I think both solutions would work. bcuz ur summarized address gives another range that encompasses the routing table subnets, it will contain the range from 10.2.0.0 – 10.2.15.255 but mine will include the range from 10.2.2.0 – 10.2.17.255. So in both cases the addresses are included.
But when checking other exams I saw a proposed solutions of 10.0.0.0/8 and 10.2.0.0/16 as a summary. But these subnets include many addresses which I think is not accurate. Will they accept any of these solutions? or which solution is the best to stick with?
Thanks again mate :)
Please can anyone help on site like this for switching
Hi Mohammad,
I’m with ya on this.. I came up with a summary address of 10.2.2.0/21… The address they used to summarize would work also, but it’s summarizing a huge range of address which is not “efficient”…
Wouldn’t 10.2.2.0/21 work also? but when I enter that in, “ip summary-address eigrp 123 10.2.2.0 255.255.248.0″, I get these routes:
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
D 10.2.8.0/24 [90/2323456] via 10.2.3.4, 00:01:11, Serial0/0
D 10.2.9.0/24 [90/2323456] via 10.2.3.4, 00:01:11, Serial0/0
D 10.2.0.0/21 [90/2195456] via 10.2.3.4, 00:00:05, Serial0/0
C 10.2.3.0/24 is directly connected, Serial0/0
Can someone please tell me why the summary address remains 10.2.0.0/21 and not 10.2.2.0/21 as I specifically stated in the command?
Is this because 255.255.248.0 looks at the first two octec. . .t . . . ohhhhhh. . .. . I get it now… :D
nevermind, Thanks!
is this stll valid please am writing my route exam on friday. please help.
man o.. keep in faith… so do i.. i’ll take my exam friday… good luck for us… :)
The “ip summary-address eigrp 123″ command can be simply summarized as “ip summary-address eigrp 123 10.0.0.0 255.0.0.0″. The question clearly states to reduce R3′s routing table to 2 “10.0.0.0″ subnets. This accomplishes that without complication. The end result is that traffic bound for any 10 network will be routed to R4 which has the more specific route to the given destination. There’s no need to be “efficient” in this case as R3 is a stub router and only has one way out.
The other ways mentioned would work to route traffic as needed, but Cisco may ding you points for not being exact with their specification in the question. They didn’t say 2 subnets of “10.2.2.0″ or “10.2.0.0″.
Thank you very much
@all4u
Thank man
Hi,
I have 2 questions.
1. at R3 we have seen no auto-summary commands is configured already and in EIGRP network if summary is configured at any point whole AS will see it as Summary address ( we have already mentioned that 10.0.0.0/8 is summary by using no auto-summary command) then why we have used ip summary-address command on R4 s0/0 interface.
2).
why we use summary on s0/0 of R4 ? why did not used at F0/0 ?
Thanks.
@adnan..
the ip summary-address command is specific to eigrp sub commands thats y we are using (if I understand ur question correctly) as there is no other way to summarize the routes.
second we cannot use the summray on FE just because the R3 is rec these routes from the R4s s0/0 interface (you can verify it from the ip route command above as well, yes if it was recieving it from e0/0 then sure y not use that (but not practical).
hello guys. are these lab sim still valuable, is there anyone who just took the exams? please tell me, i have to take my exams soon,
is the same ip in the exam or another one
Passed today with 965/1000 , all simulation are from digitaltut exactly , still REV7 is tottaly valid 100 % .. 2 new question MCQ , simulations are OSF,IPV6,Redistribution ,PBR .
Thanks to digitaltut and all of you those who posted comments here….
Really its great site……cheers…
can somebody please share the .pkt files if you have? Thanks in advance
Thanks to Digitaltut. I passed my ccnp route with 925 the day b4 yesterday (16/11). The labs were the same but few changes in IP adds, router names/locations. For those that are yet to take, this is d right site for u. Pls understand and concentrate on the given parameters.
This particular lab was not given to me but I worked on eigrp ospf red sim, ospf sim, ipv6 ospf virtual link sim & policy based routing sim. Good-luck.
we can use effective summarization 10.2.0.0 255.255.240.0 coz 4 bits in 3rd octect are same for all route
@All
Did anyone noticed that in the picture network 10.2.3/-24 is connected to s0/0 but in the output it says directly connected to s0/1. very starange isn’t t.
FYI @Mohammed and @gillman u dont use wildcard mask in the summary address, just normal subnet mask
I;m confused if this LAB is included in the exam? Please confirm
It was not included in my exam today.
hello all
i cleared the exam with 930/1000. this was not in my exam today.. except this all the sims were there.. same concept but IPs were different
gud luck for all
Wrote ROUTE today…sim not in exam…there was a mcq based roughly on “eigrp stub recieve only”
so this exam EIGRP Stub Sim is not included in the real exam right guys?
Hi, get the same result with different configuration
just write on R3
R3(conf-route)#no eigrp stub reci
R3(conf-route)#eigrp stub
and on R4 write
R4(conf-route)#eigrp stub
then you will get the following on R3
R3#sho ip rout
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 2 subnets
C 172.16.1.0 is directly connected, Loopback0
C 172.16.2.0 is directly connected, Loopback1
10.0.0.0/24 is subnetted, 2 subnets
D 10.2.2.0 [90/2195456] via 10.2.3.4, 00:10:57, Serial0/0
C 10.2.3.0 is directly connected, Serial0/0
is that correct or I’m missing sth?
Hello Mustafa,
If u configure R4 as stub, it will only adv eigrp routes connected and summary (default options). So in R3′s routing table networks 10.2.x.x other than 10.2.2.x and 10.2.3.x are missing. That is not the purpose of the question although it ends up with only two 10.x.x.x routes.
BR
thanks for the confirmation guys… so this LAB is not included in the actual exam. cheers!
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 2 subnets
C 172.16.1.0 is directly connected, Loopback0
C 172.16.2.0 is directly connected, Loopback1
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
D 10.2.0.0/16 [90/2195456] via 10.2.3.4, 00:00:07, Serial0/0
C 10.2.3.0/24 is directly connected, Serial0/0
I’m getting the output as above, i’m unable to get the 172.16.0.0/24 as only one subnet as shown above.
Am I doing it wrong?
@Pradeep Those are you Loopback interfaces… read up a little on summarization and it will clear up… memorization will fog your mind.
HI all i will write exam tomorrow who passed the exam please tell me that is there any new lab.
Hi All
I passed the exam today !!! Many of You know Me Last time When I passed The CCNA exam I remember All the Question and i send to you all also and its very helpfull to U all !!! Dont Worry Friends this time Also I remember All the Question !!! In exam I got 50 question
Out of that three are Similator
2 drag and drop
Friends Any one Want the Question Please Update the Mail Id Or Send the Mail to the mail id : dononearth0@gmail.com ( as u know )
Better U send the Mail So that I can Quick reply to You All
Help other God will help You !!!
Ur Friend Ved Prakash INDIA
Hi All4u
thanks for sharing the GNS3 files, but what is the secret for “policy based routing” sim ?
Regards
zakaryae
Friends, how many hotspots are in the exam ? and could anyone share it ?
Thank you in advance
Dear all4u!!!!
Thanks a million.
Your topo is so helpful.
Great effort for our learning.
THANK YOU SHAHID to share me latest dump, i passed yesterday i used dumps nonentity.338q.vce or actual test v 6.2 all questions from those dumps those are 100% valid and sims are from digitultut.com same sims only ip address and are change,4 sims ( Eigpr and ospf redistribute / ospf stub / ipv6 virtual-link / pbr ) and read question carefully.
latest dumps actual test v 6.2 link http://www.4shared.com/office/J1iP8WU_/642-902.html .
Some ppl report getting all 5 SIMs in real exam, but most ppl report not getting this EIGRP Stub SIM. Commit it to memory just in case.
in summary i think the optimal solution :
R4(config-if)#ip summary-address eigrp 123 10.2.0.0 255.255.240.0
in real exam (I mean GNS3) when you enter ip summary-address eigrp 1 10.2.0.0 255.255.240.0 or ip summary-address eigrp 1 10.2.0.0 255.255.0.0 or ip summary-address eigrp 1 10.0.0.0 255.0.0.0 in every case it will show you :
10.0.0.0/8 is variably subnetted, 3 subnets, 3 masks
D 10.2.0.0/16 [90/2681856] via 10.2.3.4, 00:01:04, Serial2/0
D 10.0.0.0/8 is a summary, 00:00:29, Null0
C 10.2.3.0/24 is directly connected, Serial2/0
hey Aftershocks
U r getting confused in the summarization because if u summarize it as you did
like 10.2.2.0 255.255.248.0
will come in the range of 10.2.0.1 – 10.2.7.254 address
and if u wanna summarize 16- bit subnet then u just have to apply ip summary-address eigrp 123 10.2.0.0 255.255.240.0
This will summarize address 0f range 10.2.0.1 – 10.2.15.254
Hello Friends,
I just started to study the ROUTE test after taking almost two years off from passing the CCNA. I am planning to take the ROUTE test in two months. Are the Sims, Drag and Drop, Questions, and everything else on this site still valid for the ROUTE test?
Thank you all!
@Mirza,
i beleived that you need to type the “no auto-summary” in R3 to eliminate the Null0.. and the result needs to be like this:
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.1.0 is directly connected, FastEthernet0/0
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
D 10.2.0.0/20 [90/2681856] via 10.2.3.2, 00:02:36, Serial0/0
C 10.2.3.0/24 is directly connected, Serial0/0
Passed 930/1000 Took exam 2 hrs ago, sims were IPV6 Virtual Link, Redistribution, Policy Based Routing, and EIGRP stub, no simlett or hotspot one D&D and a whole lot of questions not on this site. I got about 10 questions related to BGP that I had never seen before. Know your BGP is my recommendation.