CCNA MODULES 16–17 EXAM ANSWERS | COMPLETE PRACTICE
QUESTIONS, ANSWERS & STUDY GUIDE 2026/2027
1. Which component is designed to protect against unauthorized communications to and from a
computer?
security center
port scanner
antimalware
antivirus
firewall - ANS ✔✔firewall
2. Which command will block login attempts on RouterA for a period of 30 seconds if there are 2 failed
login attempts within 10 seconds?
RouterA(config)# login block-for 10 attempts 2 within 30
RouterA(config)# login block-for 30 attempts 2 within 10
RouterA(config)# login block-for 2 attempts 30 within 10
RouterA(config)# login block-for 30 attempts 10 within 2 - ANS ✔✔RouterA(config)# login block-for 30
attempts 2 within 10
3. What is the purpose of the network security accounting function?
to require users to prove who they are
to determine which resources a user can access
to keep track of the actions of a user
to provide challenge and response questions - ANS ✔✔to keep track of the actions of a user
4. What type of attack may involve the use of tools such as nslookup and fping?
access attack
reconnaissance attack
denial of service attack
,worm attack - ANS ✔✔reconnaissance attack
7. Which example of malicious code would be classified as a Trojan horse?
malware that was written to look like a video game
malware that requires manual user intervention to spread between systems
malware that attaches itself to a legitimate program and spreads to other programs when launched
malware that can automatically spread from one system to another by exploiting a vulnerability in the
target - ANS ✔✔malware that was written to look like a video game
8. What is the difference between a virus and a worm?
Viruses self-replicate but worms do not.
Worms self-replicate but viruses do not.
Worms require a host file but viruses do not.
Viruses hide in legitimate programs but worms do not. - ANS ✔✔Worms self-replicate but viruses do
not.
9. Which attack involves a compromise of data that occurs between two end points?
denial-of-service
man-in-the-middle attack
extraction of security parameters
username enumeration - ANS ✔✔man-in-the-middle attack
10. Which type of attack involves an adversary attempting to gather information about a network to
identify vulnerabilities?
reconnaissance
DoS
dictionary
man-in-the-middle - ANS ✔✔reconnaissance
12. What is the purpose of the network security authentication function?
, to require users to prove who they are
to determine which resources a user can access
to keep track of the actions of a user
to provide challenge and response questions - ANS ✔✔to require users to prove who they are
13. Which firewall feature is used to ensure that packets coming into a network are legitimate responses
to requests initiated from internal hosts?
stateful packet inspection
URL filtering
application filtering
packet filtering - ANS ✔✔stateful packet inspection
14. When applied to a router, which command would help mitigate brute-force password attacks against
the router?
exec-timeout 30
service password-encryption
banner motd $Max failed logins = 5$
login block-for 60 attempts 5 within 60 - ANS ✔✔login block-for 60 attempts 5 within 60
16. What feature of SSH makes it more secure than Telnet for a device management connection?
confidentiality with IPsec
stronger password requirement
random one-time port connection
login information and data encryption - ANS ✔✔login information and data encryption
17. What is the advantage of using SSH over Telnet?
SSH is easier to use.
SSH operates faster than Telnet.
SSH provides secure communications to access hosts.
QUESTIONS, ANSWERS & STUDY GUIDE 2026/2027
1. Which component is designed to protect against unauthorized communications to and from a
computer?
security center
port scanner
antimalware
antivirus
firewall - ANS ✔✔firewall
2. Which command will block login attempts on RouterA for a period of 30 seconds if there are 2 failed
login attempts within 10 seconds?
RouterA(config)# login block-for 10 attempts 2 within 30
RouterA(config)# login block-for 30 attempts 2 within 10
RouterA(config)# login block-for 2 attempts 30 within 10
RouterA(config)# login block-for 30 attempts 10 within 2 - ANS ✔✔RouterA(config)# login block-for 30
attempts 2 within 10
3. What is the purpose of the network security accounting function?
to require users to prove who they are
to determine which resources a user can access
to keep track of the actions of a user
to provide challenge and response questions - ANS ✔✔to keep track of the actions of a user
4. What type of attack may involve the use of tools such as nslookup and fping?
access attack
reconnaissance attack
denial of service attack
,worm attack - ANS ✔✔reconnaissance attack
7. Which example of malicious code would be classified as a Trojan horse?
malware that was written to look like a video game
malware that requires manual user intervention to spread between systems
malware that attaches itself to a legitimate program and spreads to other programs when launched
malware that can automatically spread from one system to another by exploiting a vulnerability in the
target - ANS ✔✔malware that was written to look like a video game
8. What is the difference between a virus and a worm?
Viruses self-replicate but worms do not.
Worms self-replicate but viruses do not.
Worms require a host file but viruses do not.
Viruses hide in legitimate programs but worms do not. - ANS ✔✔Worms self-replicate but viruses do
not.
9. Which attack involves a compromise of data that occurs between two end points?
denial-of-service
man-in-the-middle attack
extraction of security parameters
username enumeration - ANS ✔✔man-in-the-middle attack
10. Which type of attack involves an adversary attempting to gather information about a network to
identify vulnerabilities?
reconnaissance
DoS
dictionary
man-in-the-middle - ANS ✔✔reconnaissance
12. What is the purpose of the network security authentication function?
, to require users to prove who they are
to determine which resources a user can access
to keep track of the actions of a user
to provide challenge and response questions - ANS ✔✔to require users to prove who they are
13. Which firewall feature is used to ensure that packets coming into a network are legitimate responses
to requests initiated from internal hosts?
stateful packet inspection
URL filtering
application filtering
packet filtering - ANS ✔✔stateful packet inspection
14. When applied to a router, which command would help mitigate brute-force password attacks against
the router?
exec-timeout 30
service password-encryption
banner motd $Max failed logins = 5$
login block-for 60 attempts 5 within 60 - ANS ✔✔login block-for 60 attempts 5 within 60
16. What feature of SSH makes it more secure than Telnet for a device management connection?
confidentiality with IPsec
stronger password requirement
random one-time port connection
login information and data encryption - ANS ✔✔login information and data encryption
17. What is the advantage of using SSH over Telnet?
SSH is easier to use.
SSH operates faster than Telnet.
SSH provides secure communications to access hosts.
