Module 02: TCP/IP Concepts Review

What class is the IP address 172.16.0.1?

Class B - [Class A: networks with large volume of hosts, first octet value range 1 to 127, subnet mask 255.0.0.0 Class B: medium to large networks, first octet value range from 128 to 191, subnet mask 255.255.0.0 Class C: smaller networks (LANS), first octet value range from 192 to 223, subnet mask 255.255.255.0 Class D: multicasting, first octet value range from 224 to 239 Class E: reserved for research, first octet value range from 240 to 255]

What's the hexadecimal equivalent of the binary number 1111 1111? a. FF b. 255 c. EE d. DD

FF

The netstat command indicates that POP3 is in use on a remote server. Which port is the remote server most likely using?

Port 110

What port, other than port 110, is used to retrieve email?

Port 143 (IMAP - Internet Message Access Protocol) - [Extra: Port 25 & 587 (SMTP - Simple Mail Transfer Protocol unencrypted & encrypted, respectively)]

What port does DNS use?

Port 53 (Domain Name Service)

Which protocol offers guaranteed delivery and is connection-oriented?

TCP

A ping command initially uses which ICMP type code?

Type 8

What are the security considerations associated with DHCP (Dynamic Host Configuration Protocol) in network environments?

dynamic allocation of network resources

Define a socket in the context of TCP/IP and discuss its role in secure communication.

endpoint for data communication

What is the importance of (and what is the significance of the SYN/ACK flags in) the three-way handshake in TCP?

establishing a reliable connection [1. Host A sends SYN packet (synchronize) with its own ISN (Initial Sequence Number) to Host B, 2. Host B responds with SYN-ACK packet with its own ISN, 3. Host A responds with ACK packet that ACKnowledges the SYN-ACK packet, then Host A begins transmitting data]

What numbering system is used to express IPv6 addresses?

hexadecimal

Select one of the differences between IPv4 and IPv6, focusing on network vulnerabilities.

identifying potential threats [IPv6 introduces enhanced security by better identifying potential threats, addressing some vulnerabilities present in IPv4.]

What is the primary function of ports in TCP/IP networking, and its contribution to the overall communication process?

identifying specific applications/services

What is the purpose of a gateway in TCP/IP within network traffic?

it acts as a secure access point to other networks

What is the significance of the Time-to-Live (TTL) field in the IP header, and how does it play a crucial role in preventing network abuse?

it prevents packet looping and network abuse [by limiting the lifespan of packets, ensuring they are not perpetually transmitted]

What role does the IP address play in securing a TCP/IP network?

it provides a unique identifier for devices

What is the equivalent consideration associated with the Data Link layer in the OSI model and its TCP/IP equivalent?

managing physical connections [The Data Link layer and its TCP/IP equivalent are responsible for managing physical connections between devices.]

On a Windows computer, what command can you enter to show all open ports being used?

netstat

TCP communication can be likened to which of the following? a. announcement over loudspeaker b. bullhorn at sporting event c. driving on a highway d. phone conversation

phone conversation

Which command verifies the existence of a node on a network?

ping

What is the importance of the IP address in a TCP/IP network from a security perspective?

providing a unique identifier for devices

What is a TCP header's purpose and its contribution to ensuring reliable and secure communication.

providing error checking and data sequencing

Which of the following is not a valid octal number? a. 5555 b. 4567 c. 3482 d. 7770

3482 (octal number system supports digits from 0 to 7)

Which of the following protocols is connectionless?

- UDP - IP

The ISN is set at which step of the TCP three-way handshake?

1 & 2

What protocol is used for reporting or informational purposes?

ICMP (Internet Control Message Protocol)

Distinguish between IPv4 and IPv6

IPv4: 32-bit addresses (8 bits x 4) IPv6: 128-bit addresses (8 bits x 6)

What does TCP/IP mean?

Transmission Control Protocol/Internet Protocol