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CCNA Access List Sim 2

February 15th, 2014 Go to comments

Question

access_list_sim2.jpg

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

access_list_sim_show_running.jpg

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 exam, just click on host C to 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 via HTTP 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: 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 (mods):

Modification 1 (Mod 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 (Mod 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 (Mod 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 (Mod 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+).

accesslist_sim2_packet_tracer.jpg

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.

accesslist2_test_http.jpg

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:

CCNA NAT SIM Question 1

CCNA NAT SIM Question 2

CCNA Frame Relay Sim

CCNA Configuration SIM Question (RIPv2 SIM)

CCNA VTP SIM

CCNA EIGRP LAB

Comments
Comment pages
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  1. Ahmed
    April 4th, 2017

    @JK 172.22.242.16 0.0.0.15 the sbnet and wildcard means 172.22.242.16 255.255.255.248
    should block servers used standard access list to block them

  2. JK
    April 4th, 2017

    @Ahmed
    OK I got it. It’s the network ID and the wildcard. But the SM should be 255.255.255.240 and not 248.
    Thanks, sir.

  3. CCNA Dumps
    April 5th, 2017

    please, provide me with the latest dumps

    szstkg1985 at gmail (dot) com

  4. Ahmed
    April 5th, 2017

    @JK soory u are right yeah it was 255.255.255.240

    thanks,,

  5. Face
    April 6th, 2017

    So whats the question here?

  6. ali
    April 8th, 2017

    can anyone please help that how to find the ip address of finance web server? its was not given when i failed the ccna exam?

  7. examam
    April 8th, 2017

    @ali did you try to click on the fin server and go to the lan card options (ip address sub mask)?

  8. examam
    April 8th, 2017

    someone who took the exam .on lab acl the ip addresses of the servers lan is the same on the exam? 172.22.242.17 – 172.22.242.30

  9. ali
    April 9th, 2017

    @examam i appreciate your responce but in the exam i was not able to click and open any device like sim only able to open console please advice.

  10. ali
    April 9th, 2017

    another msq was there route to a network/host depends on what?
    a)Administrative distance
    b)administrative distance/Metric
    c
    d
    which to select?

  11. ali
    April 9th, 2017

    @examam so i am planning again to apply as i only get 698 marks
    should i use 172.22.242.17 for finance server or 172.22.242.30? as destination?

  12. examam
    April 9th, 2017

    @ali
    question for you number (1)was the 172.22.242.17 – 172.22.242.30 Server LAN network had the same range ip ? or the router2 f0/1 int. had the ip 172.22.242.30?

    (2)when you say you have console access to which devices exactly?

    i cant believe that they didn’t give some basic ip’s.

  13. examam
    April 9th, 2017

    A router receives information about network 192.168.10.0/24 from multiple sources. What will the
    router consider the most reliable information about the path to that network?

    a directly connected interface with an address of 192.168.10.254/24
    a static route to network 192.168.10.0/24
    a RIP update for network 192.168.10.0/24
    an OSPF update for network 192.168.0.0/16
    a default route with a next hop address of 192.168.10.1
    a static route to network 192.168.10.0/24 with a local serial interface configured as the next hop
    Answer: A
    Explanation:
    When there is more than one way to reach a destination, it will choose the best one based on a
    couple of things. First, it will choose the route that has the longest match; meaning the most
    specific route. So, in this case the /24 routes will be chosen over the /16 routes. Next, from all the
    /24 routes it will choose the one with the lowest administrative distance. Directly connected routes
    have an AD of 1 so this will be the route chosen.

  14. ccna
    April 10th, 2017

    Is acl sim still valid?

  15. bob
    April 11th, 2017

    at the and of configuration do i need to save this from running config to startup config?

  16. Anonymous
    April 11th, 2017

    Is there anyone have an idea about new exam how is it like coz i examed recently but I don’t know I had heard from afew people some new questions it came these days , please if anyone have any good news about this rumor

  17. jmwas
    April 12th, 2017

    kindly send me the latest dumps,am sitting for ccna 200-125 on 19th april.mail at
    engmwaskabiru@gmail(dot)com

  18. king-9936
    April 19th, 2017

    Which component of the Cisco SDN solution serves as the centralized management system?
    A. Cisco OpenDaylight
    B. Cisco ACI
    C. Cisco APIC
    D. Cisco IWAN

    please someone tell me the answer ….

  19. jm93
    April 20th, 2017

    Is this still applying? It’s up to date?
    * 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.

  20. ccna
    April 20th, 2017

    c is the answer

  21. .
    April 20th, 2017

    In the exam, is this Sim multiple choice?

  22. TheGreatestOne
    April 20th, 2017

    Passed today with 92+, ACL sim still valid….

  23. Sachini
    April 21st, 2017

    @TheGreatestOne and 9tut
    Coluld u please tell me what are teh valid labs

  24. Anonymous
    April 21st, 2017

    B: Cisco ACI
    this is from cisco SDN solutions website
    ACI’s broad ecosystem extends the comprehensive services and management of the data center platform
    Learn how Cisco Application Centric Infrastructure can help you manage your data center, speed up application deployments, and deliver services more quickly.

  25. ahmad
    April 22nd, 2017

    does ips of servers be given in exam ???

  26. hellfish
    April 22nd, 2017

    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
    i got these from an out side website ….i think they are true better then nothing right

  27. Anonymous
    April 23rd, 2017

    I have an “If, Then” question.
    If the question reads “allow only host C access to the Financial Web server,” implying host C also has access to other resources on the same server, then the ACL should read as follows:

    Access-list 100 permit host 192.168.33.3 host 172.22.242.23
    Access-list 100 deny tcp any eq www host 172.22.242.23
    Access-list 100 permit ip any any

    However,

    If the question reads “allow host C only access to the Financial Web server,” implying host C hos no additional access to other resources on the same server, then the ACL should read as follows:

    access-list 100 permit tcp host 192.168.33.3 host 172.22.242.23 eq 80
    access-list 100 deny ip host 192.168.33.3 host 172.22.242.23
    access-list 100 permit ip any any

  28. semo
    April 23rd, 2017

    hello guys, could someone please explain why the ip addresses of the others servers are ;172.22.242.16 0.0.0.15

    Modification 1 (Mod 1):

    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

  29. Sulabh
    April 23rd, 2017

    Can someone please explain if acl mod 3 comes in the exam then do we have to enter the three commands of modification 3 or all the commands which are shown above the modifications?

  30. BIGBEAR
    April 26th, 2017

    Hello everyone, can someone send me the last question dump CCNA Exam 200-125
    I will take ccna exam next month
    rngeanmongkoln at gmail.com

    Best Regards,

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