Which wild card mask will enable a network administrator to permit access to the Internet for only
hosts that are assigned an address in the range of 192.168.8.0 through 192.168.15.255?
A.
0.0.255.255
B.
0.0.0.0
C.
0.0.3.255
D.
0.0.0.255
E.
0.0.7.255
Explanation:
Wildcard mask summarization example:
This list describes how to summarize a range of networks into a single network for ACL
optimization. Consider these networks.
192.168.32.0/24
192.168.33.0/24
192.168.34.0/24
192.168.35.0/24
192.168.36.0/24
192.168.37.0/24
192.168.38.0/24
192.168.39.0/24
The first two octets and the last octet are the same for each network. This table is an explanation
of how to summarize these into a single network.
The third octet for the above networks can be written as seen in this table, according to the octet
bit position and address value for each bit.
Since the first five bits match, the above eight networks can be summarized into one network
(192.168.32.0/21 or 192.168.32.0 255.255.248.0). All eight possible combinations of the three loworder bits are relevant for the network ranges in question. This command defines an ACL that
permits this network. If you subtract 255.255.248.0 (normal mask) from 255.255.255.255, it yields
0.0.7.255.
access-list acl_permit permit ip 192.168.32.0 0.0.7.255
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