CCNA Access List Sim 2
Question
A network associate is adding security to the configuration of the Corp1 router. The user on host C should be able to use a web browser to access financial information from the Finance Web Server. No other hosts from the LAN nor the Core should be able to use a web browser to access this server. Since there are multiple resources for the corporation at this location including other resources on the Finance Web Server, all other traffic should be allowed.
The task is to create and apply a numbered access-list with no more than three statements that will allow ONLY host C web access to the Finance Web Server. No other hosts will have web access to the Finance Web Server. All other traffic is permitted.
Access to the router CLI can be gained by clicking on the appropriate host.
All passwords have been temporarily set to “cisco”.
The Core connection uses an IP address of 198.18.196.65
The computers in the Hosts LAN have been assigned addresses of 192.168.33.1 – 192.168.33.254
Host A 192.168.33.1
Host B 192.168.33.2
Host C 192.168.33.3
Host D 192.168.33.4
The servers in the Server LAN have been assigned addresses of 172.22.242.17 – 172.22.242.30
The Finance Web Server is assigned an IP address of 172.22.242.23.
The Public Web Server is assigned an IP address of 172.22.242.17
Answer and Explanation
(Note: If you are not sure how to use access-list, please check out my access-list tutorial at: http://www.9tut.com/access-list-tutorial, also some modifications about the access-list have been reported so you should read the “Some modifications” section at the end of this question to understand more. You can also download this sim to practice (open with Packet Tracer) here: http://www.9tut.com/download/9tut.com_Access-list_sim2.pkt
Corp1>enable (you may enter “cisco” as it passwords here)
We should create an access-list and apply it to the interface which is connected to the Server LAN because it can filter out traffic from both Sw-2 and Core networks. The Server LAN network has been assigned addresses of 172.22.242.17 – 172.22.242.30 so we can guess the interface connected to them has an IP address of 172.22.242.30 (.30 is the number shown in the figure). Use the “show running-config” command to check which interface has the IP address of 172.22.242.30.
Corp1#show running-config
We learn that interface FastEthernet0/1 is the interface connected to Server LAN network. It is the interface we will apply our access-list (for outbound direction).
Corp1#configure terminal
Our access-list needs to allow host C – 192.168.33.3 to the Finance Web Server 172.22.242.23 via web (port 80)
Corp1(config)#access-list 100 permit tcp host 192.168.33.3 host 172.22.242.23 eq 80
Deny other hosts access to the Finance Web Server via web
Corp1(config)#access-list 100 deny tcp any host 172.22.242.23 eq 80
All other traffic is permitted
Corp1(config)#access-list 100 permit ip any any
Apply this access-list to Fa0/1 interface (outbound direction)
Corp1(config)#interface fa0/1
Corp1(config-if)#ip access-group 100 out
Notice: We have to apply the access-list to Fa0/1 interface (not Fa0/0 interface) so that the access-list can filter traffic coming from both the LAN and the Core networks. If we apply access list to the inbound interface we can only filter traffic from the LAN network.
In the real exam, just click on host C and open its web browser. In the address box type http://172.22.242.23 to check if you are allowed to access Finance Web Server or not. If your configuration is correct then you can access it.
Click on other hosts (A, B and D) and check to make sure you can’t access Finance Web Server from these hosts.
Finally, save the configuration
Corp1(config-if)#end
Corp1#copy running-config startup-config
(This configuration only prevents hosts from accessing Finance Web Server via web but if this server supports other traffic – like FTP, SMTP… then other hosts can access it, too.)
Notice: In the real exam, you might be asked to allow other host (A, B or D) to access the Finance Web Server so please read the requirement carefully.
Some modifications:
Modification 1:
| permit host B from accessing finance server | access-list 100 permit ip host 192.168.33.2 host 172.22.242.23 |
| deny host B from accessing other servers (not the whole network) | access-list 100 deny ip host 192.168.33.2 172.22.242.16 0.0.0.15 |
| permit everything else | access-list 100 permit ip any any |
Modification 2:
| Only allow Host C to to access the financial server | access-list 100 permit ip host 192.168.33.3 host 172.22.242.23 |
| Not allow anyone else in any way communicate with the financial server | access-list 100 deny ip any host 172.22.242.23 |
| Allow all other traffic | access-list 100 permit ip any any |
Modification 3:
| - Host C should be able to use a web browser(HTTP)to access the Finance Web Server | access-list 100 permit tcp host 192.168.33.3 host 172.22.242.23 eq 80 |
| - Other types of access from host C to the Finance Web Server should be blocked - All access from hosts in the Core or local LAN to the Finance Web Server should be blocked |
access-list 100 deny ip any host 172.22.242.23 (because the requirement says we can not use more than 3 statements so we have to use “any” here for the hosts in the Core and hosts in local LAN) |
| - All hosts in the Core and local LAN should be able to access the Public Web Server * | access-list 100 permit ip any host (If the question asks this, surely it has to give you the IP of Public Web Server) but in the exam you should use “access-list 100 permit ip any any” |
Modification 4:
| Host C should be able to use a web browser to access the financial web server | access-list 100 permit tcp host 192.168.33.3 host 172.22.242.23 eq 80 |
| Other types of access from host C to the finance web server should be blocked | access-list 100 deny ip host 192.168.33.3 host 172.22.242.23 |
| All hosts in the core and on the local LAN should be able to access the Public web server * | access-list 100 permit ip any host (The IP of Public Web Server will surely be given in this question) but in the exam you should use “access-list 100 permit ip any any” |
* There are some reports about the command of “All hosts in the core and on the local LAN should be able to access the Public web server” saying that the correct command should be “access-list 100 permit ip any any”, not “access-list 100 permit ip any host (IP of Public Web Server)”. Although I believe the second command is better but maybe you should use the first command “access-list 100 permit ip any any” instead as some reports said they got 100% when using this command (even if the question gives you the IP address of Public Web Server). It is a bug in this sim.
(Note: Don’t forget to apply this access list to the suitable interface or you will lose points
interface fa0/1
ip access-group 100 out
And in the exam, they may slightly change the requirements, for example host A, host B instead of host C… so make sure you read the requirement carefully and use the access-list correctly)
I created this sim in Packet Tracer v5.2.1 so you can practice with it. You will need new version of Packet Tracer to open it (v5.1+).
Download this sim here
Notice: After typing the commands above, if you make a “ping” from other hosts (PC0, PC1, PC3) then PC4 (Finance Web Server) can still reply because we just filter HTTP traffic, not ICMP traffic. To generate HTTP traffic, select “Web Browser” in the “Desktop” tab of these PCs. When a web browser opens, type the IP address of Finance Web Server and you can see how traffic flows in Simulation Mode.
And notice that in the initial configuration of this sim the Core network can ping Finance Web Server. We have to create an access-list that can filter this traffic too.
Other lab-sims on this site:
@jans
You must use v1.1.6 for the VCE player
@ adnan. Standard acl ( 1-99) extended acl (100- 199)
so i believe the configuration is correct.
I have just passed CCNA exam with 986/1000 – ACL1, ACL2 and EIGRP with AS 122.
Everything questions from 9tut. Thank so much
Good luck Everybody.
Thanxs Galicia and james, got the point.
acl1,ac2 and eigrp in exam yesterday
Can someone link which questions these are “acl1,ac2 and eigrp in exam yesterday?”
from ACL2 mod 3, can anyone tell me this modification3 had come in exam? can anyone remember ? please help me to know…
my exam is Tomorrow whats the laps in exam ….. please help my
Passed today with 1000/1000. A BIG THANK TO 9tut. 99% got from 9tut.
This Sim was in today exam with modification 3.
@sabrina
Yes. I got ACL2 mod 3 in today exam. 9tut answer is exactly correct. For the 3rd line, make sure you type “access-list 100 permit ip any any”. Good Luck!
Hi all I think that ACL Modification 1 is wrong
Correct is : access-list 100 permit tcp host 192.168.33.2 host 172.22.242.23 eq 80
access-list 100 deny tcp host 192.168.33.2 172.22.242.16 0.0.0.15 eq 80
access-list 100 permit ip any any
or not ?
@ Villiam
In modification 1, it doesn’t mention about a particular service. Therefore, host B should be allowed access all services of Finance Server and blocked all services of other servers.
So you should use ‘permit ip’ instead of ‘permit tcp’ and should not add ‘eq xx’ at the end.
@ Asanka
Ouuuuu of course, Thanks for your reply and understanding
Gave my exam today passed with 1000 marks (100%). Labs coming Eigrp, ACL1 and ACL2 (modification 3, with D as the intended host).
One question from Etherchannel (Section: New CCNA- New Questions 2, the question which came in the paper was Q4).
thanks to 9tut for telling me about the new questions and all the questions are here in 9tut. I studied from watson dumps.
I have passed the CCNA exam today with a perfect score! I studied Watsons vce file. Lab were EIGRP , ACL 1 and 2 mod 3. There were questions from VRRP and Etherchannel.
Hi all , I had passed the CCNA exam today score 1000/1000 I studied only cisco netacad and 9tut questions.
Today were labs EIGRP and ACL1 and ACL2 mod 2
Thanks for all and Good Luck ;)
NEED immediate help
In Modification 1,
why we cant use wild card mask 0.0.0.7 instead 0.0.0.15
thank you
@Asanka
thank you so much……
@sl,
ok, let’s do the calculation according to wild card mask 0.0.0.7…
wild card mask 0.0.0.7 means subnet mask is 255.255.255.248. right?
Then the increment is 256-248 = 8
So the 1st usable ip address of the subnet is: 172.22.242.17
Last usable ip address is: 172.22.242.22
correct?
But according to the question, servers have assigned ip range from 172.22.242.17 to 172.22.242.30
Also, the Financil server has been assigned 172.22.242.23
Therefore, we have to use subnet mask of 255.255.255.240. That means the wild card mask is 0.0.0.15
Hope you understood :)
thank you asanka
but in there they mention “deny host B from accessing other servers (not the whole network)”
so if we choose the wild card mask 0.0.0.15 , there we use the “whole network”.
also we need to block Public Web Server and DNS so we can use 0.0.0.7
am i correct?
in the note we cant find a ip address of dns. but in the pact dns =172.22.242.20.
can you guys help me to resolve this matter ?
Since the first rule we were allowed access to the server you need a second we just completely block the entire network. On this and it turns 0.0.0.15
And do not forget that you can do the job just three teams
@sl,
don’t be confused.
the first thing you should understand is the network 172.22.242.16/28 is allocated only for servers. there is no any other device other than servers in this network. question mentions it as ‘Server LAN’.
next, ‘not the whole network’ means ‘not the entire network including other hosts and devices’. the question asks to block other servers (Server LAN) but not the entire network.
If you type, ‘access-list 100 deny ip host 192.168.33.2 any’ then you are blocking the whole network. To avoid that we should type ‘access-list 100 deny ip host 192.168.33.2 (Server LAN)’.
In the diagram, they have shown only three servers. but since they have given the ip range for all the servers, we should block that ip range.
:-)) thank you asanka.
you done a great help to me. thank you again.
No worries.. Glad that i could help you
Passed today 931/1000 labs where EIGRP, ACL1 & ACL2 Mod 3. Also had 4 drag and drops all from 9TUT. On ACL2 access-list 100 permit ip any any worked.
i passed my test yesterday
thanks 9tut
all question from here
Passed today 945/1000
Thanks to examtut.278q.vce,Watson.314q and 9tut simulations.
EIGRP LAB,ACL 1 and ACL 2 was there. Good luck everyone!!
@kasun ,kindly share with us any new question ?
Passed today with 1000/1000
Just ACL ACL2 mod3 and EIGRP 221
All question in Watson dumps and 9tut. Good luck everyone and thanks 9tut.
i am giving my xam on 29th of oct and i am looking for dumps. please inbox me at sureshverna@gmail.com
thank u
Anyone have the latest dumps? Saleemmazyck@yahoo
Just Passed CCNA. Scored 945/1000. Questions are ACL, ACL1 and eigrp AS 22. Tanks alot. Contact me if U need latest dumps.
Hi 9tut,
In the main answer the deny statement is “Corp1(config)#access-list 100 deny tcp any host 172.22.242.23 eq 80″ but in the Mod 3 “access-list 100 deny ip any host 172.22.242.23″ are both correct ?
Alhamdullilah passed with more than 980 .. sims are acl 1 2 eigrp 100% quiz from 9 tut.
passed exam today 1000/1000……thanks 9tut!!!
Mushi in the mod3 it’s written that any other type should be allow so no TCP/UDP… so the only choice is “access-list 100 deny ip any host 172.22.242.23″
In the main answer they just ask to deny access to everyone to access the WEB BROWSER on this server so “no IP but TCP and eq 80 is mandatory”…
hello IBM , PLEASE help me with the latest dumps i am planning to retake my ccna 200-120 exam in two weeks time, please help me so that i cannot fail the exam again,,thanx in advance, you can send dumps and any other materials to codetwentyten@yahoo.com
i have given my exam today. eigrp with 12 AS, acl 1 and acl 2 with modulation 3 were the simulations…..
Passed exam today, Same simulations different IP on EIGRP AS, SAME ACL, ACL-2.
Hi IBM , I am going to take the CCNA Exam within one or two week so please send me the latest dumps to (sel111@rediffmail.com)
need a clarification ,
In mod 3 and mod 4 question B , are they same ?
immidiate help would be appriciated.
Hai guys just passed my ccna exam, got 100%. Dis is my email id saneeshsidharthan@hotmail.com If any one need dumps. Just study from this site you’ll get pass
Thanks for the explanation Xiao
Passed my CCNA exam today @980. Thx to 9tut.
ACL1 (the one with 3 multiple questions), ACL2 ( 3 statement to be entered on int f0/1 out) and EIGRP 122 troubleshooting; same as above EIGR 212 but with minor changes ( correct router eigrp 22 with 122 on new router, also noticed one network command missing, and on ISP router , there was one wrong n/w command on the other router connecting to ISP).
Readers, please pay attention for ACL2, the real exam doesn’t provide any hosts IP addresses, you’ll have to dig them out yourself from directly connected interface: show run.
To be frank, I spent about 10 mins on this question trying to hammer out Finance and Host C IPs.
Make sure you understand what your are doing cz this exam is not easy to pass if you are guessing.
Nice one Dany! well done.
You say that the real exam doesn’t provide any hosts IP addresses and you’ll have to dig them out yourself. How do you do this if you can only console into the Corp1 server? Thanks
Kindly Answer
Reference to two commands:-
access-list 100 permit tcp host
access-list 100 permit ip host
What is the difference between tcp and ip keyword? which one is suitabe? you have mentioned both in modificatinos.
Hi all,
Can we use “wr” command instead of using “copy running-config startup-config” to save configuration?
This config is incorrect. Need wildcard masks after addresses
Hello Jules,
They want to test you subletting knowledge
The ACL2 figure displayed here above is real, but ignore the IPs details given below it, cz you need to make that list yoursef.
As you can see on the figure interface , there are some .254, .30, .1, .2,.3: these are host part of the int subn/w:
Proceed as follows:
1. Display Int Ips on the Router Corp by clicking on the PC Console and entering command: show run, you will see both Ips and masks
2. Write down the N/w potion of each interface(eg Interface f0/1 : Ip add 172.16.223.254 255.255.255.0 = 172.16.223 .0 and add host part= .3, so the host C has an IP add: 172.16.223.3)
Cheers Dany, that makes sense. I take it this was the same for the finance web server too?