network - internet protocols - July 6 2025

Which of the following is a valid IPv4 address? a. 256.0.0.1 b. 10.0.0.1.5 c. 172.16.0.300 d. 192.168.0.1

d. 192.168.0.1

How many octets are in an IPv4 address?

4

What is the valid range for each octet in an IPv4 address?

0 to 255

Which IPv6 address type is used for local subnet communication?

Link-local address

Which IPv6 address type is routable on the Internet?

Global Unicast address

What is the primary difference between HTTP and HTTPS?

HTTPS encrypts data using SSL/TLS

Which port does HTTP use?

Port 80

Which port does HTTPS use?

Port 443

What does the 'S' in HTTPS stand for?

Secure

Which protocol is used to transfer email between servers?

SMTP

What is the primary function of DNS?

Translate domain names to IP addresses

Which DNS record is used for email servers?

MX record

Which tool can test if DNS is the issue when a domain doesn't load?

Try accessing by IP address

Which DHCP message does a client send to request a specific IP after offers?

DHCP Request

Which DHCP message is used to request more settings without a new IP?

DHCP Inform

Which DHCP message renews the IP lease?

DHCP Request

Which protocol assigns IP addresses dynamically?

DHCP

What does DHCP Discover do?

Finds available DHCP servers

What does NAT stand for?

Network Address Translation

What is the function of NAT?

Translates private IPs to a public IP

What is a potential issue NAT creates for IoT devices?

Limited public IPs for device-specific services

How can a web server behind NAT be accessed from the internet?

Port forwarding

Which protocol retrieves emails and keeps them on the server?

IMAP

Which protocol retrieves emails and downloads them to the client?

POP3

Which command in SMTP resets state tables?

RSET

Which encryption method upgrades an SMTP connection to secure?

STARTTLS

Which command traces the route to a host?

traceroute

Which command shows the local routing table?

route print

Which command shows network connections and ports?

netstat

Which command renews IP address on Windows?

ipconfig /renew

Which command lists current IP config on Windows?

ipconfig /all

What is the key advantage of UDP over TCP?

Lower latency and faster transmission

Which protocol is better for streaming or VoIP?

UDP

Which protocol guarantees delivery and uses acknowledgments?

TCP

Which protocol supports connectionless communication?

UDP

Which protocol includes error checking and retransmission?

TCP

Which port is used by FTP control connection?

Port 21

Which FTP mode typically gives better speed over Ethernet?

Active mode

What does FTP stand for?

File Transfer Protocol

What protocol is secure for copying files over SSH?

SCP

Which protocol is used for real-time voice and video?

RTP

What protocol works with RTP for fast, unreliable delivery?

UDP

Why is NAT problematic for VoIP?

It can increase latency or block direct connections

What type of certificate is needed for HTTPS?

SSL/TLS certificate

Which organization issues SSL certificates?

Certificate Authority (CA)

What is the role of SSL/TLS in HTTPS?

Encrypts data between client and server

Which hashing algorithm is commonly used in certificates?

SHA-256

What should you do if you get an invalid HTTPS certificate warning?

Report it to the website owner

Does HTTPS require a browser plugin?

No

What is the loopback address in IPv4?

127.0.0.1

Which class of IPv4 address is 192.168.1.1?

Class C

What type of IPv6 address starts with fe80::?

Link-local

What is the subnet mask for a Class B IP address?

255.255.0.0

Which IP class provides the most host addresses?

Class A

Which protocol uses port 25?

SMTP

Which protocol uses port 53?

DNS

Which protocol uses port 110?

POP3

Which protocol uses port 143?

IMAP

Which protocol uses port 3389?

RDP

What is the purpose of a CNAME DNS record?

Alias one domain name to another

What is a PTR DNS record used for?

Reverse DNS lookup

Which DNS record type maps a domain to an IP address?

A record

Which protocol is used to resolve domain names to IPs?

DNS

What command checks DNS resolution in Windows?

nslookup

What is the default lease time in many DHCP servers?

24 hours

What port does DHCP use for client-server communication?

Port 67

What DHCP step comes before DHCP Request?

DHCP Offer

What DHCP message is used to relinquish an IP address?

DHCP Release

What is a DHCP reservation?

Pre-assigns an IP to a MAC address

What port does secure SMTP typically use?

Port 465

Which email protocol allows syncing folders across devices?

IMAP

What protocol is used for sending email?

SMTP

Which port is commonly used by POP3 with SSL?

995

What is the main disadvantage of using POP3?

It typically downloads and deletes messages from the server

Which of the following is a private IP address? a. 10.0.0.5 b. 172.32.0.1 c. 192.0.2.1 d. 8.8.8.8

a. 10.0.0.5

What is port forwarding?

Redirects communication requests to specific internal hosts

What is the benefit of NAT?

Allows multiple devices to share a single public IP

Which protocol is used for NAT traversal in VoIP?

STUN

What range is reserved for APIPA addresses?

169.254.0.0/16

What does the 'ping' command test?

Connectivity between two hosts

What does 'ipconfig /flushdns' do?

Clears the DNS resolver cache

What is the use of 'tracert' in Windows?

Traces the path to a destination host

What does 'arp -a' display?

Shows the ARP cache

Which command tests network path and performance in one?

pathping

Which protocol secures wireless communication?

WPA2

Which protocol is often used in VPNs?

IPSec

What protocol is used to sync time across devices?

NTP

Which port does SSH use?

Port 22

What protocol is used to retrieve web pages securely?

HTTPS

What type of protocol is SNMP?

Network management protocol

What port does SNMP use?

Port 161

What is the function of an SNMP trap?

Unsolicited alert from agent to manager

What is a broadcast address in IPv4?

255.255.255.255

What is the purpose of ICMP?

Sends diagnostic and error messages

Which protocol is used to establish a voice call session?

SIP

What does QoS stand for in networking?

Quality of Service

Which protocol helps prioritize voice traffic?

DiffServ

What is jitter in network communication?

Variation in packet arrival times

Which protocol is used to deliver streaming media?

RTP