QUESTION 1
Where does routing occur within the 200-125 vce DoD TCP/IP reference model?
A. application
B. internet
C. network
D. transport
Correct Answer: B Explanation

Explanation:
The picture below shows the comparison between TCP/IP model & OSI model. Notice that the Internet Layer of TCP/IP is equivalent to the Network Layer 200-125 exam which is responsible for routing decision.

QUESTION 2
Refer to exhibit:
Which destination addresses will be used by Host A to send data to Host C? (Choose two.)
A. the IP address of Switch 1
B. the MAC address of Switch 1
C. the IP address of Host C
D. the MAC address of Host C
E. the IP address of the router’s E0 interface
F. the MAC address of the router’s E0 interface
Correct Answer: CF

Explanation:
While transferring data through many different networks, the 200-125 pdf source and destination IP addresses are not changed. Only the source and destination MAC addresses are changed. So in this case Host A will use the IP address of Host C and the MAC address of E0 interface to send data. When the router receives this data, it replaces the source MAC address with it own E1 interface’s MAC address and replaces the destination MAC address with Host C’s MAC address before sending to Host C.

QUESTION 3
For what two purposes does the Ethernet protocol use physical addresses? (Choose two.)
A. to uniquely identify devices at Layer 2
B. to allow communication with devices on a different network
C. to differentiate a Layer 2 frame from a Layer 3 packet
D. to establish a priority system to determine which device gets to transmit first
E. to allow communication between different devices on the same network
F. to allow detection of a remote device when its physical address is unknown
Correct Answer: AE

Explanation:
Physical addresses or MAC addresses 200-125 dumps are used to identify devices at layer 2.
MAC addresses are only used to communicate on the same network. To communicate on different network we have to use Layer 3 addresses (IP addresses) -> B is not correct.
Layer 2 frame and Layer 3 packet can be recognized via headers. Layer 3 packet also contains physical address ->
On Ethernet, each frame has the same priority to transmit by default -> All devices need a physical address to identify itself. If not, they can not communicate ->

QUESTION 17
Refer to the exhibit.
Based on the information given, which switch will be 200-125 elected root bridge and why?
A. Switch A, because it has the lowest MAC address
B. Switch A, because it is the most centrally located switch
C. Switch B, because it has the highest MAC address
D. Switch C, because it is the most centrally located switch
E. Switch C, because it has the lowest priority
F. Switch D, because it has the highest priority
Correct Answer: E Explanation
Explanation:
To elect the root bridge in the 200-125 LAN, first check the priority value. The switch having the lowest priority will win the election process. If Priority Value is the same then it checks the MAC Address; the switch having the lowest MAC Address will become the root bridge. In this case, switch C has the lowest MAC Address so it becomes the root bridge.

Reference: http://www.cisco.com/c/en/us/training-events/training-certifications/exams/current-list/200-125-ccna.html

Related: https://www.vcecert.com/network-appliance-ns0-157-exam/