CCNA Exhibit

CCNA Lab Console:

Access List Lab - Block PING Traffic

An Irish record label - "Celtic Records" - has three stores networked using the schema below. Each store consists of one LAN and all routers are completely configured and in full working order both locally and across the serial links. However, the Network Manager - Mary Maguire - wants access control list statements created that will block PING traffic through the Sligo router while allowing all other traffic to pass.

Please complete the Network Manager's requirements using no more than three lines and apply where needed.

The routers have been configured with the following specifications:

The routers are named Sligo, Belfast and Dublin.
RIP is the routing protocol.
The clocking is provided on the Serial 0 interface.
The secret password on the all routers is "cisco".
The subnet mask on all interfaces is the default mask.

Host B

Tips: Use Host B to connect the Sligo router. Toggle F11 to access/exit fullscreen mode.

Successful Lab Completion

You will not be told this on the actual exam but you have successfully completed the Lab.

Good job!

? - Lab Help

Ping uses ICMP - think extended access-list (protocol - Internet Control Messaging Protocol)
Block - prevent - etc - think "deny"
Placement -- extended ACL - think as close to the source of the traffic entering the Sligo router.

Write down:

Three lines
Sligo
Host B (serially connected to Sligo)
PW: cisco
deny
icmp
inbound traffic -- "any host" -- is pretty generic and will do the job in this case
E0: 192.168.149.1
S0: 192.168.199.1

Write down ACL input statements (3 lines - extended range 100 - 199):

access-list 101 deny icmp any host 192.168.149.1
access-list 101 deny icmp any host 192.168.199.1
access-list 101 permit ip any any (remember a permit statement must follow deny statements)

Write down how you will apply the ACL: (traffic entering the router through e0 and s0 (in))

int e0
ip access-group 101 in
int s0
ip access-group 101 in

Now input your statements into the Command Line Interface. No matter what -- if you go over 15 minutes on an actual exam Lab - get to the "Privilege EXEC mode" prompt and input "copy run start".