Given the access-lists:
"access-list 120 deny tcp 126.96.36.199 0.0.3.255 any eq http
access-list 120 permit ip any any"
Then this is the traffic:
a)source ip 188.8.131.52, destination=http
b) source ip 184.108.40.206, destination=http
Are the traffic above on a) and b) denied or permitted?
I am kind of confused on how to visualize this. I tried to write source IP in binary format:
3rd and 4th octect only->
.32.14 = 00100000.00001110
But honestly I can't visualize how to determine whether the inverse mask 0.0.3.255 would deny or permit this. Can you help me understand how I should approach this problem?
Reread your posting, looks like I misunderstand your question.Here is the correction:
220.127.116.11 written in binary format is (only 3rd and 4th octes are ahown)
and the mask is
the topmost 6 bits should match exactly, so address with the following pattern
000011xx xxxxxxxx (where x= 0 or 1)
will match the source address field of ACL
The address range that match the ACL is
00001100 00000000 to 00001111 11111111
witten in digtal format, it is
12.0 to 15.255
So, the answer is A.