CCST Network Protocols and Services 2 — Questions and Answers
Question 1: What is the purpose of NAT (Network Address Translation)?
- Encrypts traffic between internal and external networks
- Maps private internal IP addresses to a public IP address for internet access (Correct answer)
- Assigns IP addresses to devices dynamically
- Resolves hostnames to MAC addresses
Correct answer: Maps private internal IP addresses to a public IP address for internet access
NAT translates private RFC 1918 addresses used inside a network to a public IP address when communicating with the internet, conserving public address space.
Question 2: Which file transfer protocol uses TCP port 21 for control and TCP port 20 for data transfer in active mode?
- SFTP
- TFTP
- FTP (Correct answer)
- SCP
Correct answer: FTP
FTP (File Transfer Protocol) uses port 21 for the control connection and port 20 for the data connection in active mode.
Question 3: A technician needs to transfer a router's IOS image using a lightweight protocol that requires no authentication and uses UDP. Which protocol should they use?
- FTP
- TFTP (Correct answer)
- SFTP
- SCP
Correct answer: TFTP
TFTP (Trivial File Transfer Protocol) uses UDP port 69 and provides simple, unauthenticated file transfers, commonly used for IOS images and config files.
Question 4: Which protocol synchronizes the clocks of networked devices and uses UDP port 123?
- DNS
- SNMP
- NTP (Correct answer)
- LDAP
Correct answer: NTP
NTP (Network Time Protocol) uses UDP port 123 to synchronize device clocks across a network to a common time source.
Question 5: What does the acronym VLAN stand for, and what is its primary purpose?
- Virtual LAN — logically segments a physical network into separate broadcast domains (Correct answer)
- Virtual Link Aggregation Network — bonds multiple interfaces
- Verified LAN — authenticates all connected devices
- Variable Length Address Network — supports CIDR addressing
Correct answer: Virtual LAN — logically segments a physical network into separate broadcast domains
A VLAN (Virtual LAN) logically divides a physical switch into multiple isolated broadcast domains, improving security and traffic management.
Question 6: Which protocol resolves IP addresses to MAC addresses on a local network segment?
- RARP
- DNS
- ARP (Correct answer)
- DHCP
Correct answer: ARP
ARP (Address Resolution Protocol) broadcasts a request on the local segment to discover the MAC address associated with a known IP address.
CCST Network Protocols and Services 2
What is the purpose of NAT (Network Address Translation)?