CREST CPSA Exam Questions With Complete Solution

CREST CPSA Exam Questions With Complete Solution What are the 7 layers of the OSI model? - CORRECT ANSWERS 1. Physical 2. Data Link 3. Network 4. Transport 5. Session 6. Presentation 7. Application How many bits and octets are there in an IPv4 address? - CORRECT ANSWERS 32 - there are four octets of 8 bits each in an IPv4 address How many bits are in an IPv6 address - CORRECT ANSWERS 128 bits What does IPv6 use instead of ARP? - CORRECT ANSWERS IPv6 uses Neighbour Discovery Protocol (NDP) What is the IP Class A range? - CORRECT ANSWERS 0-127 What is the IP Class B range? - CORRECT ANSWERS 128-191 What is the IP Class C range? - CORRECT ANSWERS 192-223 What is the IP Class D range? - CORRECT ANSWERS reserved What is the IP Class E range? - CORRECT ANSWERS reserved What does TCP stand for? - CORRECT ANSWERS Transmission Control Protocol What does UDP stand for? - CORRECT ANSWERS User Datagram Protocol What does SCTP stand for? - CORRECT ANSWERS Stream Control Transmission Protocol What sort of protocol is TCP? - CORRECT ANSWERS A connection-oriented protocol that uses a three-way handshake. Compare TCP and UDP - CORRECT ANSWERS UDP is faster than TCP but UDP is less reliable than TCP. What protocols use TCP? - CORRECT ANSWERS Used by HTTP/HTTPS What protocols use UDP? - CORRECT ANSWERS SNMP, DNS, NTP, IKE What does ICMP stand for? - CORRECT ANSWERS Internet Control Message Protocol What is ICMP used for? - CORRECT ANSWERS Used to see if a device is up or down. What attacks are associated with ICMP? - CORRECT ANSWERS Ping of death, smurf attack and ICMP flooding. What is MAC? - CORRECT ANSWERS Media Access Control is a physical 48 bit address which is used to uniquely identify a device. What is ARP? - CORRECT ANSWERS Address Resolution Protocol - resolves IPV4 address to MAC addresses What is CSMA/CD? - CORRECT ANSWERS Used by ethernet to prevent collisions What is a token ring? - CORRECT ANSWERS A communication standard like ethernet but less chance of collisions, uni-directional, half duplex. What does FHRP stand for? - CORRECT ANSWERS First Hop Redundancy Protocol What does FHRP do? - CORRECT ANSWERS Protects default gateways by allowing two or more router to provide backup for that address. Meaning if the active router fails, the backup router takes it's place. How does the backup router detect if the active router is down? (FHRP) - CORRECT ANSWERS Both Active and Backup routers send a HELLO broadcast message periodically, so if a HELLO message is not received by the backup router then it assumes the active router is dead.