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GK One-Line Question & Answer

15541+ short questions with short answers, covering every category and sub-category on the site — no long articles to scroll through. Good for a fast recap before an exam, or a few minutes of daily practice.

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Computer Fundamentals → Introduction to Computer 38

Binary XOR used in error detection because?
XOR of data with parity = 0 if no error
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Ones complement addition: end-around carry means?
Add the carry bit back to LSB
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Negative zero in ones complement is represented as?
11111111
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The biased exponent in IEEE 754 single precision uses bias of?
127
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Which protocol provides IP address autoconfiguration in IPv6?
SLAAC (Stateless Address Autoconfiguration)
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ICMPv6 NDP (Neighbor Discovery Protocol) replaces which IPv4 protocols?
ARP and ICMP router discovery
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Which IPv6 address type replaces ARP?
Link-local solicited-node multicast
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OSPF area 0 is called?
Backbone area
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BGP is classified as which type of routing protocol?
EGP (Exterior Gateway Protocol)
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BGP uses which transport protocol?
TCP (port 179)
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EIGRP is a?
Cisco proprietary advanced distance vector protocol
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MPLS (Multi Protocol Label Switching) forwards packets based on?
Short fixed-length labels — faster than IP routing
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SD-WAN stands for?
Software Defined Wide Area Network
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SDN (Software Defined Networking) separates?
Data and control planes
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OpenFlow protocol is used in?
SDN to communicate between controller and forwarding devices
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Network Function Virtualization (NFV) means?
Running network functions (firewall, LB) as software on standard hardware
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Which DNS record type maps hostname to IPv4 address?
A
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Which DNS record maps hostname to IPv6 address?
AAAA
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DNS MX record is used for?
Mail server routing
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DNS CNAME record creates?
Alias from one hostname to another
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Reverse DNS lookup uses which DNS record?
PTR
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DNS SOA record contains?
Start of Authority: primary NS, admin email, serial, refresh, retry, expire
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DNS TTL (Time To Live) controls?
How long DNS resolvers cache the record
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DNSSEC adds to DNS?
Cryptographic signatures to prevent DNS spoofing
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DoH (DNS over HTTPS) provides?
Encrypted DNS queries via HTTPS (port 443)
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DoT (DNS over TLS) encrypts DNS using?
TLS on port 853
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DHCP lease time determines?
How long a device keeps its assigned IP before renewal
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DHCP DORA process stands for?
Discover, Offer, Request, Acknowledge
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APIPA address is assigned when?
DHCP server is unavailable — self-assigned fallback address
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Which protocol is used for dynamic routing in ISP backbone networks?
BGP
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Spanning Tree Protocol (STP) prevents?
Layer 2 switching loops
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RSTP (802.1w) improves on STP by?
Faster convergence (seconds vs minutes)
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Which protocol allows a switch to become a DHCP client?
DHCP client (standard)
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LACP (Link Aggregation Control Protocol) is used for?
Bundling multiple physical links into one logical link
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Port mirroring/SPAN is used for?
Copying traffic from one port to another for analysis
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802.1Q VLAN tagging adds how many bytes to Ethernet frame?
4
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VLAN ID range in 802.1Q is?
1-4094
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QinQ (802.1ad) double tagging is used for?
Service provider VLANs (VLAN tunneling for customer traffic)
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Computer Fundamentals → Number System 2

Binary number 10000000000 has how many zeros?
10
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Hexadecimal is more convenient than binary for memory addresses because?
Each byte is represented by exactly 2 hex digits
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