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Q. 71
Which statement about an IP network is true?
A.A broadcast source MAC contains all zeros.
B.A MAC address is part of the physical layer of the OSI model.
C.MAC addresses are used by bridges to make forwarding decisions: IP addresses are used by routers.
D.IP addresses are now a flat addressing scheme: MAC addresses use a hierarchical addressing scheme.
Answer: C
Explanation: A bridge uses MAC addresses to make routing decisions whereas a routers uses IP addresses to makes its routing decisions.
Incorrect Answers:
A is incorrect; for broadcasts MAC uses the address is all ones, or X’FF’ for each octet. B is incorrect; the MAC address is part of the Data Link Layer.
D is incorrect; it is reversed. MAC is Flat Addressing, and IP is hierarchical.
Steve McQuerry. Interconnecting Cisco Network Devices. (Cisco Press: 2000) pages
Q. 72
Which statement about the Committed Information Rate (CIR) is true?
A.It is the rate, in bits per second, at which the Frame Relay switch agrees to transfer data
B.It is the clock speed (port speed) of the connection (local loop) to the Frame Relay cloud
C.It is the maximum number of bits that the switch can transfer during any Committed Rate Measurement Interval
D.It is a signaling standard between the CPE device and the FR switch. It is responsible for managing the connection and maintaining status between the devices.
Answer: A
Explanation: CIR is the rate in bits per second at which the service provided guarantees that data will be transferred.
Incorrect Answers:
B is incorrect; clock rate defines the clock speed.
C is incorrect; CIR can be exceeded.
D is incorrect; CIR is not a signaling standard.
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