Which of these is not a layer in the OSI model that primarily handles end-to-end logical communication between applications?
Network Layer
Transport Layer
✓
Data Link Layer
Physical Layer
Correct Answer
Transport Layer
The Network Layer handles host-to-host communication, the Data Link Layer handles node-to-node communication, and the Physical Layer handles bit transmission. The Transport Layer is primarily responsible for end-to-end logical communication between applications, making it the one that fits the description, while the question asks for the one that does *not* primarily handle it.
Question 2
Which of these is not a private IP address range defined by RFC 1918?
169.254.0.0/16
✓
192.168.0.0/16
10.0.0.0/8
172.16.0.0/12
Correct Answer
169.254.0.0/16
The ranges 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 are the three private IP address ranges defined by RFC 1918. The 169.254.0.0/16 range is for Automatic Private IP Addressing (APIPA), which is not a private range defined by RFC 1918.
Question 3
Which of these common network services does not primarily use UDP as its transport protocol?
DHCP
DNS
HTTP
✓
TFTP
Correct Answer
HTTP
DNS (for client queries), DHCP, and TFTP primarily use UDP for their operations due to its connectionless and low-overhead nature. HTTP primarily uses TCP for its reliable, connection-oriented data transfer.
Question 4
Which of these network devices does not operate at Layer 3 (Network Layer) of the OSI model?
Router
Layer 3 Switch
Hub
✓
Firewall
Correct Answer
Hub
Routers, Layer 3 Switches, and Firewalls primarily operate at Layer 3 (Network Layer) by making forwarding decisions based on IP addresses. A Hub operates at Layer 1 (Physical Layer) by simply repeating signals.
Question 5
Three of these DNS record types are used for forward lookups. Which one is not?
A
CNAME
MX
PTR
✓
Correct Answer
PTR
PTR (Pointer) records are used for reverse DNS lookups, mapping an IP address to a hostname. A records map a hostname to an IPv4 address, CNAME records create aliases for hostnames, and MX records specify mail servers.
Question 6
Three of these tools report path, connection or name-resolution detail. Which one does not, and only tests whether a host is reachable?
traceroute
ping
✓
netstat
nslookup
Correct Answer
ping
Traceroute (or tracert on Windows) is primarily used to display the path (hops) packets take to a destination. Ping tests basic reachability, netstat displays active network connections, and nslookup queries DNS.
Question 7
Three of these OSI layers work with addressed, logically structured data units. Which one does not, and handles only raw bits on the medium?
Network Layer
Transport Layer
Physical Layer
✓
Data Link Layer
Correct Answer
Physical Layer
The Data Link Layer is primarily responsible for error detection and correction on frames, as well as media access control. The Physical Layer deals with the raw bit stream, not error-free frame transmission.
Question 8
Which of these CIDR prefixes does not allow for more than 100 usable host addresses?
/25
/26
✓
/24
/23
Correct Answer
/26
A /25 prefix allows for 126 usable hosts, a /24 allows for 254 usable hosts, and a /23 allows for 510 usable hosts. A /26 prefix allows for 62 usable hosts, which is not more than 100.
Question 9
Which of these protocols is not primarily designed for secure remote file transfer?
SFTP
SCP
TFTP
✓
FTPS
Correct Answer
TFTP
SFTP (SSH File Transfer Protocol), SCP (Secure Copy Protocol), and FTPS (FTP Secure) are all protocols designed for secure remote file transfer, typically involving encryption. TFTP (Trivial File Transfer Protocol) is a simple, unauthenticated, and unencrypted file transfer protocol.
Question 10
Which of these is not an example of a link-state routing protocol?
EIGRP
✓
BGP
OSPF
IS-IS
Correct Answer
EIGRP
OSPF (Open Shortest Path First) and IS-IS (Intermediate System to Intermediate System) are link-state routing protocols. BGP (Border Gateway Protocol) is a path-vector routing protocol. EIGRP (Enhanced Interior Gateway Routing Protocol) is classified as an advanced distance-vector or hybrid routing protocol, not a link-state protocol.
Question 11
Three of these DHCP messages are sent by the client. Which one is not?
DHCP Release
DHCP Offer
✓
DHCP Request
DHCP Discover
Correct Answer
DHCP Offer
DHCP Discover, DHCP Request, and DHCP Acknowledge are messages initiated or sent by the DHCP client. DHCP Offer is a message sent by the DHCP server in response to a Discover message, offering an IP configuration to the client.
Question 12
Which of these steps is not part of troubleshooting after physical connectivity has been verified?
Verify IP address configuration
Check DNS resolution
Ping the default gateway
Check cable connections
✓
Correct Answer
Check cable connections
Verifying IP address configuration, pinging the default gateway, and checking DNS resolution are steps performed after confirming basic physical connectivity. Checking cable connections is itself a primary step in verifying physical connectivity.
Question 13
Three of these protocols do not provide reliable, ordered delivery. Which one does?
TCP
✓
ICMP
IP
UDP
Correct Answer
TCP
TCP (Transmission Control Protocol) is responsible for reliable, ordered, and error-checked delivery of data streams. UDP (User Datagram Protocol) provides unreliable, connectionless delivery. IP (Internet Protocol) handles logical addressing and routing, and ICMP (Internet Control Message Protocol) is used for diagnostic and error reporting.
Question 14
Which of these IP addresses is not a valid host address within the subnet 192.168.1.64/28?
192.168.1.79
✓
192.168.1.70
192.168.1.78
192.168.1.65
Correct Answer
192.168.1.79
For the subnet 192.168.1.64/28, the network address is 192.168.1.64. The subnet mask is 255.255.255.240, giving a block size of 16. The next network address is 192.168.1.80. Therefore, the broadcast address is 192.168.1.79, and the valid host range is 192.168.1.65 through 192.168.1.78. Thus, 192.168.1.79 is the broadcast address, not a valid host address.
Question 15
Which of these common network services is not primarily associated with the reliable transfer of data?
SMTP
FTP
HTTP
TFTP
✓
Correct Answer
TFTP
HTTP, FTP, and SMTP are all application layer protocols that rely on TCP for reliable data transfer. TFTP (Trivial File Transfer Protocol) uses UDP, making it an unreliable file transfer protocol, suitable for simple transfers where reliability is handled at a higher layer or not critical.