Chapter 11: Networking Fundamentals and Devices (Set-5)
A network inside one organization that uses private web portals and internal DNS is typically an
A Extranet network
B Public internet
C PAN network
D Intranet network
An intranet is a private internal network used by employees. It may use internal DNS names and portals, and access is controlled. It improves secure sharing of documents and internal services.
Allowing vendors to access only a purchase portal through a secure login is a typical
A Intranet setup
B Bus topology
C Extranet setup
D PAN setup
An extranet gives limited access to selected outsiders like vendors. It shares specific resources securely without exposing full internal systems, using authentication and access control to reduce risks.
High bandwidth but poor video calls often indicates high
A Disk fragmentation
B Latency or jitter
C Screen resolution
D File compression
Video calls need stable timing. High latency delays packets, and jitter varies delay, causing choppy audio/video. Even with high bandwidth, unstable timing and packet loss degrade real-time communication.
In a bus topology, the main performance issue with many devices is
A DNS fails always
B IP becomes static
C VLAN stops working
D Collisions increase
Bus topology shares one medium. When many devices transmit, collisions rise, causing retransmissions and slow speed. This is why modern Ethernet moved to switched networks with fewer collisions.
A star network using a hub instead of a switch mainly suffers from
A No broadcast traffic
B No MAC addresses
C One collision domain
D No IP addresses
A hub broadcasts signals to all ports, so all devices share one collision domain. Simultaneous transmissions collide, lowering performance. Switches isolate collision domains per port, improving speed.
A switch learns the MAC-to-port mapping primarily from
A Source MAC field
B Destination IP field
C Subnet mask value
D DNS name entry
When frames arrive, the switch reads the source MAC and records which port it came from. This builds the MAC table so later frames can be forwarded only to the correct destination port.
When a switch receives a unicast frame for an unknown MAC, it will
A Send to router
B Drop permanently
C Flood within VLAN
D Convert to broadcast
Unknown unicast frames are flooded to all ports in the same VLAN except the incoming port. When the destination replies, the switch learns its MAC location and can then forward efficiently.
The device that separates broadcast domains in normal operation is a
A Hub device
B Repeater device
C Cable tester
D Router device
Routers do not forward Layer-2 broadcasts by default, so each router interface forms a separate broadcast domain. This limits broadcast traffic and improves network stability and security.
A VLAN is best understood as
A Physical cable type
B Internet encryption
C Logical LAN separation
D Wi-Fi speed test
A VLAN logically divides a switch into separate networks. Devices in different VLANs are separated at Layer 2, reducing broadcast traffic and improving security, even though they share the same switch hardware.
Communication between different VLANs usually requires
A Routing between VLANs
B A repeater only
C A hub only
D Coax cable
Different VLANs are separate Layer-2 networks. To communicate between them, traffic must be routed by a router or Layer-3 switch using inter-VLAN routing, applying rules and policies if needed.
Collision domains become smaller in switched Ethernet because each switch port is
A Same collision domain
B Same broadcast domain
C Separate collision domain
D Same DNS domain
Each switch port is its own collision domain, so collisions are minimized. This allows multiple devices to communicate simultaneously without sharing a single medium like hubs or old bus networks.
Broadcast storms are controlled in networks mainly by
A Stronger passwords
B Proper segmentation
C Bigger hard drives
D Higher monitor resolution
Broadcast storms occur when broadcast traffic grows excessively, often due to loops or misconfiguration. Using VLANs, loop prevention features, and good design reduces broadcast flooding and keeps networks stable.
Twisted pair cable length beyond limits can cause
A Signal attenuation
B Faster DNS cache
C Higher encryption
D Lower IP usage
As copper cable length increases, signals weaken and become noisy due to attenuation. This leads to errors and retransmissions. Following recommended Ethernet cable length limits helps maintain reliable performance.
Fiber optic is preferred over copper in electromagnetic noisy areas because fiber is
A Always cheaper
B Easy to splice
C EMI immune
D Uses MAC tables
Fiber transmits light, so electromagnetic interference does not affect it. This makes it highly reliable in industrial environments. It also supports longer distances and higher bandwidth than many copper options.
A modem is required in many broadband setups because it performs
A Modulation/demodulation
B MAC filtering
C VLAN tagging
D Packet routing
A modem converts digital data into signals suitable for the ISP medium and converts back again. This is essential for DSL/cable services where the line signaling differs from Ethernet on the LAN side.
NAT on a home router mainly allows
A One-to-many printers
B Many-to-many VLANs
C Many-to-one internet
D One-to-one MACs
NAT translates many private IP addresses to one public IP for internet access. It conserves IPv4 addresses and adds basic protection by hiding internal device addresses from direct inbound connections.
A typical symptom of wrong subnet mask on a PC is
A Monitor flickers
B Keyboard lags
C Printer overheats
D Local reach fails
With an incorrect subnet mask, a PC may think devices are local when they are not, or vice versa. This breaks local communication or forces traffic incorrectly to gateway, causing connectivity issues.
If default gateway is missing, a computer usually can access
A Only the internet
B Only DNS server
C Same subnet only
D Only Wi-Fi SSID
Without a gateway, the computer can communicate only with devices in the same local subnet. It cannot reach other networks like the internet because it has no router address to forward external traffic.
When DNS is incorrect but connectivity exists, users often can
A Ping IP addresses
B Change MAC addresses
C Increase bandwidth
D Disable NAT only
If DNS fails, name resolution does not work, but IP routing can still work. Users may reach servers by IP address but cannot open websites by name until DNS settings are corrected.
A strong Wi-Fi security setup should include
A WEP encryption
B WPA2/WPA3 only
C Open hotspot
D WPS PIN enabled
WPA2 or WPA3 provides strong encryption. WEP is weak, and open networks allow easy interception. Disabling WPS reduces brute-force risk, and strong passwords plus firmware updates improve overall safety.
Hidden SSID improves security mainly by
A Strong encryption
B Faster Wi-Fi speed
C Very little protection
D Higher bandwidth
Hiding SSID only stops the name from being broadcast openly. The network can still be discovered, and it does not encrypt data. Real security comes from WPA2/WPA3 and strong passwords.
MAC filtering is not full security because MAC addresses can be
A Spoofed easily
B Encrypted strongly
C Changed by DNS
D Removed by VLAN
Attackers can capture a permitted MAC address and imitate it, bypassing MAC filtering. MAC filtering can add minor control, but strong WPA2/WPA3 encryption remains the main protection.
In crowded Wi-Fi environments, 2.4 GHz often performs worse due to
A Extra fiber usage
B IP conflict only
C DNS caching
D Channel congestion
2.4 GHz has fewer non-overlapping channels and is widely used, leading to interference from nearby routers and devices. This causes slower speed and unstable connections, especially in apartments.
WPA3 improves protection against password guessing mainly by
A Shorter SSID
B Bigger antenna
C Stronger handshake
D Faster router CPU
WPA3 uses improved authentication that makes offline password guessing harder. It strengthens the handshake process and improves encryption, making Wi-Fi safer when combined with a strong passphrase.
A broadcast domain in a VLAN-based switch is typically limited to
A Same VLAN only
B Whole building
C Whole internet
D Whole WAN link
Broadcasts normally stay within the same VLAN. VLANs split the network into separate broadcast domains, reducing unnecessary traffic and improving performance and security across different groups.
A collision domain becomes larger when using a
A Switch device
B Router device
C Hub device
D Fiber link
Hubs share one collision domain for all ports, so collisions increase as devices transmit. Switches isolate collision domains, and routers don’t participate in collision domains in the same way.
A proxy server provides privacy mainly by
A Increasing Wi-Fi signal
B Hiding client IP
C Changing subnet mask
D Boosting upload speed
A proxy can act as an intermediary, so external servers see the proxy’s address rather than the client’s direct IP. Proxies can also filter content and cache pages for performance.
Load balancing is most useful when a service needs
A More keyboard speed
B More screen color
C High availability
D More file folders
Load balancing distributes requests across multiple servers so no single server overloads. If one server fails, others can continue serving users. This improves uptime, speed, and reliability for heavy traffic services.
When traceroute shows delay starting after a certain hop, it suggests
A NIC driver crash
B Wrong SSID name
C Printer offline
D Issue beyond hop
Traceroute displays each router hop and response time. If delay begins after a particular hop, congestion or routing problems are likely at that point or further along the path, helping pinpoint trouble.
A cable tester showing “split pair” indicates
A Wrong wire pairing
B Broken fiber core
C Low DNS speed
D High router heat
Split pair means wires are connected to correct pins but paired incorrectly, causing interference and errors. The cable may link but perform poorly, leading to slow speed and packet loss.
In a switched network, excessive broadcasts can still reduce speed because broadcasts are
A Routed to internet
B Stored in DNS
C Flooded to many
D Encrypted by hub
Switches forward broadcast frames to all ports within the VLAN. Too many broadcasts consume bandwidth and CPU resources, slowing the network. VLAN segmentation and good design help reduce this load.
If two devices have same static IP, the best fix is to
A Make IP unique
B Disable switch ports
C Change monitor size
D Use WEP security
Static IPs must be unique in the same subnet. Assign different addresses or move one device to DHCP with a reserved lease. Proper IP planning prevents repeated conflicts.
A DNS server that responds slowly mainly increases
A File compression speed
B Router signal power
C Website opening delay
D Printer spool size
Slow DNS delays name resolution, so websites take longer to start loading even if data transfer is fast afterward. Using reliable DNS servers and caching helps improve browsing responsiveness.
A WAN link can have good bandwidth but poor performance if
A CPU fan is loud
B Packet loss exists
C RAM is high
D SSD is full
Packet loss causes retransmissions, reducing effective throughput and making real-time services unstable. Even with high bandwidth, loss leads to buffering, slow downloads, and poor call quality.
A correct reason for using IPv6 in modern networks is
A Smaller MAC size
B Faster keyboard input
C Huge address space
D Lower monitor pixels
IPv6 provides a massive number of addresses compared to IPv4, reducing address shortage and dependence on NAT. It supports modern networking needs as more devices connect worldwide.
An IPv4 private range commonly used in homes is
A 7.0.0.0/8
B 11.0.0.0/8
C 55.0.0.0/8
D 10.0.0.0/8
10.0.0.0/8 is a private IPv4 range used inside organizations and some home networks. Private ranges are not routed on the public internet and usually access the internet using NAT.
The main security risk of leaving router admin default is
A Easy takeover
B Faster downloads
C Better latency
D Strong encryption
Default admin credentials are widely known. Attackers can log in and change DNS, open ports, or disable security. Changing admin username/password and updating firmware reduces takeover risks.
A secure Wi-Fi setup includes turning off
A WPA2 encryption
B Router firewall
C WPS feature
D Guest isolation
WPS can be exploited, especially via PIN attacks. Disabling WPS and using WPA2/WPA3 with strong passwords reduces unauthorized access risk. Keeping firmware updated improves security further.
A correct meaning of “throughput” is
A Cable thickness
B Router brand name
C DNS domain name
D Actual data rate
Throughput is the real usable data transferred per second after overhead, delays, and retransmissions. It can be lower than bandwidth due to protocol overhead, congestion, interference, or packet loss.
In wireless, “jitter” mainly means
A Higher bandwidth always
B Extra IP addresses
C Variable packet delay
D Stronger MAC filtering
Jitter is variation in packet arrival times. It damages voice and video quality because audio/video streams need steady timing. Reducing interference and congestion improves jitter and call stability.
Using a VPN on public Wi-Fi mainly protects
A Data confidentiality
B Monitor brightness
C Router antenna
D IP conflict always
A VPN encrypts traffic between your device and the VPN server, protecting against eavesdropping on public Wi-Fi. It improves privacy and security, especially for sensitive browsing and logins.
A “default gateway” should be in the same subnet because otherwise
A DNS cannot cache
B VLAN cannot tag
C Wi-Fi cannot scan
D ARP cannot reach
To send packets to the gateway, the PC must find the gateway’s MAC using ARP, which works only within the local subnet. If gateway IP is outside subnet, the PC can’t reach it.
A network loop on switches can cause
A Faster routing
B Broadcast storm
C Less interference
D Better NAT speed
Loops can make frames circulate endlessly, multiplying broadcasts and overwhelming the network. This can bring the network down. Loop prevention features and correct cabling prevent such problems.
A basic reason for using a switch instead of hub is
A More collisions
B More flooding
C Better efficiency
D Less security
Switches forward frames only where needed using MAC learning, reducing collisions and unnecessary traffic. This improves speed and reliability compared to hubs, especially when many devices use the network.
When a device gets “169.254.x.x” address, it usually indicates
A DHCP failed
B NAT succeeded
C DNS is perfect
D VLAN is trunk
169.254.x.x is an APIPA address assigned when DHCP is unavailable. The device can’t get a valid network IP, so it often cannot reach the internet. Checking DHCP server/router fixes it.
A correct definition of “default route” is
A Route for MACs
B Route for DNS
C Route for unknowns
D Route for VLAN
A default route is used when no specific route matches a destination network. It usually points to the gateway toward the internet. Without it, the router may not know where to send unknown traffic.
In an enterprise, network segmentation mainly improves
A Keyboard speed
B Printer ink
C Screen contrast
D Security control
Segmentation isolates departments and limits who can access what. It reduces attack spread, controls broadcasts, and supports better policy enforcement. VLANs and routing rules are common segmentation tools.
A correct example of “network documentation item” is
A Desktop wallpaper
B Mouse DPI value
C IP addressing plan
D Font style list
Documentation includes IP ranges, VLAN IDs, device names, port maps, and configurations. It helps troubleshooting and maintenance by showing how the network is structured and how devices are connected.
If Wi-Fi works close to router but fails in far room, best solution is
A Add access point
B Disable encryption
C Reduce passwords
D Use WEP only
Weak signal in distant areas needs better coverage. Adding an access point or mesh node extends Wi-Fi properly. Disabling security is unsafe and does not reliably fix signal strength issues.
A key reason to use 5 GHz Wi-Fi over 2.4 GHz is
A Longer range always
B Less interference
C Works without router
D Needs no password
5 GHz typically has more channels and less congestion than 2.4 GHz, giving better speed and stability in crowded areas. Range may be shorter, but performance is often better near the router.