SIMULATION
A corporation wants to add security to its network. The requirements are:
Host C should be able to use a web browser (HTTP) to access the Finance Web Server.
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.
All hosts in the Core and on local LAN should be able to access the Public Web Server.
You have been tasked to create and apply a numbered access list to a single outbound interface. This
access list can contain no more than three statements that meet these requirements.
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 198.18.209.65.
The computers in the Hosts LAN have been assigned addresses of 192.168.78.1 – 192.168.78.254.
host A 192.168.78.1
host B 192.168.78.2
host C 192.168.78.3
host D 192.168.78.4
The Finance Web Server has been assigned an address of 172.22.146.17.
The Public Web Server in the Server LAN has been assigned an address of 172.22.146.18.
Answer: See the explanation
Explanation:
Please see below explanation part for details answer steps:We should create an access-list and apply it to the interface that is connected to the Server LAN
because it can filter out traffic from both S2 and Core networks. To see which interface this is, use
the “show ip int brief” command:From this, we know that the servers are located on the fa0/1 interface, so we will place our
numbered access list here in the outbound direction.
Corp1#configure terminal
Our access-list needs to allow host C – 192.168125.3 to the Finance Web Server 172.22.109.17 via
HTTP (port 80), so our first line is this:
Corp1(config)#access-list 100 permit tcp host 192.168.125.3 host 172.22.109.17 eq 80
Then, our next two instructions are these:
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.
This can be accomplished with one command (which we need to do as our ACL needs to be no more
than 3 lines long), blocking all other access to the finance web server:
Corp1(config)#access-list 100 deny ip any host 172.22.109.17
Our last instruction is to allow all hosts in the Core and on the local LAN access to the Public Web
Server (172.22.109.18)
Corp1(config)#access-list 100 permit ip host 172.22.109.18 any
Finally, apply this access-list to Fa0/1 interface (outbound direction)
Corp1(config)#interface fa0/1
Corp1(config-if)#ip access-group 100 outNotice: We have to apply the access-list to Fa0/1 interface (not Fa0/0 interface) so that the accesslist can filter traffic coming from both the LAN and the Core networks.
To verify, just click on host C to open its web browser. In the address box
type http://172.22.109.17 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. Then, repeat to make sure they can reach the public server at 172.22.109.18. Finally,
save the configuration
Corp1(config-if)#end
Corp1#copy running-config startup-config