81. Which cloud networking service provides on-demand virtual networks?
- a) VPC (Virtual Private Cloud)
- b) CDN (Content Delivery Network)
- c) IaaS (Infrastructure as a Service)
- d) SaaS (Software as a Service)
Answer: A - VPC allows creation of isolated cloud networks with customizable IP ranges and subnets.
82. What is the purpose of 6to4 tunneling in IPv6?
- a) To transmit IPv6 packets over IPv4 networks
- b) To encrypt IPv6 traffic
- c) To convert IPv4 addresses to IPv6
- d) To prioritize IPv6 traffic
Answer: A - 6to4 encapsulates IPv6 packets within IPv4 for cross-protocol communication (prefix: 2002::/16).
83. Which routing protocol uses autonomous system numbers (ASNs)?
- a) BGP
- b) OSPF
- c) RIP
- d) EIGRP
Answer: A - BGP (Border Gateway Protocol) uses ASNs to identify networks in inter-domain routing.
84. What is the primary benefit of Anycast routing?
- a) Improved redundancy and reduced latency
- b) Higher bandwidth allocation
- c) End-to-end encryption
- d) Automatic IP address assignment
Answer: A - Anycast routes traffic to the nearest server instance (used by DNS root servers, CDNs).
85. Which protocol is used for IPv6 neighbor discovery?
- a) ICMPv6
- b) ARP
- c) DHCPv6
- d) NDP
Answer: D - NDP (Neighbor Discovery Protocol) replaces ARP in IPv6 (uses ICMPv6 messages).
86. What does VXLAN stand for in network virtualization?
- a) Virtual Extensible LAN
- b) Virtual Cross-Layer Address Network
- c) VLAN Extension Protocol
- d) VPN Exchange LAN
Answer: A - VXLAN extends Layer 2 networks over Layer 3 with 24-bit segment IDs (vs VLAN's 12-bit).
87. Which cloud service model provides serverless computing?
- a) FaaS (Function as a Service)
- b) PaaS (Platform as a Service)
- c) IaaS (Infrastructure as a Service)
- d) SaaS (Software as a Service)
Answer: A - FaaS (e.g., AWS Lambda) runs code in response to events without managing servers.
88. What is the purpose of a CNAME record in DNS?
- a) To create an alias for a domain name
- b) To map a domain to an IPv6 address
- c) To authorize email servers
- d) To define name servers
Answer: A - CNAME (Canonical Name) points one domain to another (e.g., www.example.com → example.com).
89. Which technology enables multiple VLANs over a single switch port?
- a) Trunking (802.1Q)
- b) Port mirroring
- c) LACP (Link Aggregation)
- d) STP (Spanning Tree Protocol)
Answer: A - Trunk ports carry tagged traffic for multiple VLANs using 802.1Q encapsulation.
90. What is the primary use of GRE tunneling?
- a) To encapsulate various protocols within IP
- b) To encrypt VPN traffic
- c) To prioritize voice traffic
- d) To filter malicious packets
Answer: A - GRE (Generic Routing Encapsulation) creates virtual point-to-point links for multi-protocol traffic.
91. Which IPv6 transition technique uses dual-stack routers?
- a) Dual IP layer
- b) Teredo tunneling
- c) 6to4
- d) ISATAP
Answer: A - Dual-stack devices run IPv4 and IPv6 simultaneously for gradual migration.
92. What is the purpose of a route reflector in BGP?
- a) To reduce full-mesh peering requirements
- b) To encrypt BGP updates
- c) To convert IPv4 routes to IPv6
- d) To prioritize AS paths
Answer: A - Route reflectors propagate BGP routes to clients without requiring full-mesh topology.
93. Which protocol is used for automatic IPv6 router discovery?
- a) NDP Router Advertisement
- b) DHCPv6
- c) OSPFv3
- d) ICMPv6 Echo Request
Answer: A - NDP's Router Advertisement (RA) messages announce IPv6 prefixes and default gateways.
94. What does CDN stand for in cloud networking?
- a) Content Delivery Network
- b) Centralized Data Node
- c) Cloud Domain Name
- d) Cryptographic Data Network
Answer: A - CDNs cache content at edge locations to reduce latency (e.g., Cloudflare, Akamai).
95. Which BGP attribute determines the best path?
- a) AS_PATH
- b) ORIGIN
- c) LOCAL_PREF
- d) All of the above
Answer: D - BGP uses multiple attributes: AS_PATH length, ORIGIN type, and LOCAL_PREF (administrative preference).
96. What is the purpose of an anycast address in IPv6?
- a) To deliver packets to the nearest interface
- b) To multicast to specific groups
- c) To provide loopback functionality
- d) To assign unique global addresses
Answer: A - Anycast addresses (from unicast space) enable load balancing and redundancy.
97. Which technology separates control and data planes in networking?
- a) SDN (Software-Defined Networking)
- b) MPLS
- c) VXLAN
- d) OSPF
Answer: A - SDN centralizes control in software (e.g., OpenFlow) while hardware handles forwarding.
98. What is the primary use of a Teredo tunnel?
- a) To traverse IPv6 through NAT devices
- b) To encrypt IPv4 traffic
- c) To prioritize gaming traffic
- d) To filter malicious packets
Answer: A - Teredo encapsulates IPv6 in UDP/IPv4 packets for NAT compatibility (prefix: 2001::/32).
99. Which cloud service provides DNS management?
- a) Route 53
- b) CloudFront
- c) Direct Connect
- d) Lambda
Answer: A - AWS Route 53 is a scalable DNS web service with traffic routing capabilities.
100. What is the purpose of PIM (Protocol Independent Multicast)?
- a) To efficiently route multicast traffic
- b) To encrypt group communications
- c) To convert unicast to broadcast
- d) To prioritize VoIP packets
Answer: A - PIM builds multicast distribution trees independent of unicast routing protocols.