Final Questions b4 exam...Urgent response wanted :)

sunny_evander

i am sitting for exam very soon and am a bit nervous... And i would appreciate if any one could plz answer them quickly

You are a network admin of network X and want to block network access from outside to device 172.16.1.1 Which access-list do u apply?

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interface serial 0
ip access-group 100 in


Correct me folks if i am wrong! Well my questions in this case is why is it in here? The telnet is to be blocked from outside to network X. So out means that the traffic will be denied after it is processed by access-list and then access-list knows that it is destined for network X.. and hence the router will drop it... What exactly will happen if we place in here? The packets will be dropped before being processed by the ACL.. So if the ACL doesnt process it how come will it know the traffic is for Network X???

EIGRP stores feasible successor in topology table and where is the topology table itself stored? in RAM or NVRAM?

What layer does CDP work on? I think the answer is Layer 2 but can any one plz explain it?

EdTheLad

So you want to block network access from outside to device 172.16.1.1.
The best way to block traffic to this device is by adding the access list to the s0 interface which is gateway into network X.
By specifying in you are telling the router to examine all packets entering this interface i.e. incoming and discard any with a destination address 172.16.1.1.If this access list was placed further downstream you are wasting router resources i.e. bandwidth,buffer space,cpu etc.
If you replaced in with out you would be policing traffic with a destination 172.16.1.1 address leaving network X which isnt gonna happen if 172.16.1.1 is a divice internal to network X.
The topology table is stored in RAM.
CDP layer 2.