Correct Answer : Option (D) : 192.168.24.43
Explanation : Class A private address range is 10.0.0.0 through 10.255.255.255. Class B private address range is 172.16.0.0 through 172.31.255.255, and Class C private address range is 192.168.0.0 through 192.168.255.255.
Correct Answer : Option (C) : Class C
Explanation : A Class C network address has only 8 bits for defining hosts: 2² - 2 = 254.
Correct Answer : Option (A) : 3 and 4
Explaination : Internet Control Message Protocol (ICMP) is used to send error messages through the network, but they do not work alone. Every segment or ICMP payload must be encapsulated within an IP datagram (or packet).
Correct Answer : Option (C) : 1, 3 and 4
Explaination : This seems like a hard question at first because it doesn't make sense. The listed answers are from the OSI model and the question asked about the TCP/IP protocol stack (DoD model). However, let's just look for what is wrong. First, the Session layer is not in the TCP/IP model; neither are the Data Link and Physical layers. This leaves us with the Transport layer (Host-to-Host in the DoD model), Internet layer (Network layer in the OSI), and Application layer (Application/Process in the DoD).
Correct Answer : Option (A) : TCP
Explanation : Although Telnet does use TCP and IP (TCP/IP), the question specifically asks about layer 4, and IP works at layer 3. Telnet uses TCP at layer 4.
Correct Answer : Option (B) : ARP
Explanation : Address Resolution Protocol (ARP) is used to find the hardware address from a known IP address.
Correct Answer : Option (A) : DNS
Explanation : DNS uses TCP for zone exchanges between servers and UDP when a client is trying to resolve a hostname to an IP address.
Correct Answer : Option (D) : 10xxxxxx
Explanation : The range of a Class B network address is 128-191. This makes our binary range 10xxxxxx.
Correct Answer : Option (C) : Application
Explanation : Both FTP and Telnet use TCP at the Transport layer; however, they both are Application layer protocols, so the Application layer is the best answer.
Correct Answer : Option (D) : enable secret Cisco
Explanation : The enable secret password is case sensitive, so the second option is wrong. To set the enable secret <password>, use the enable secret <password> command from global configuration mode.