It -220 Chapter 5 Page 187-191 Q and a 1-37 Odd.

IT -220
Chapter 5 page 187-191
Q and A 1-37 odd.

1. What are the four layers of the TCP/IP model? i. Application – Defines the applications used to process requests and what ports and sockets are used. I. (This layer is used to process requests from hosts and to make sure a connection is made to an appropriate port.) ii. Transport – Defines the type of connection established between hosts and how acknowledgements are sent. iii. Internet – Defines the protocols used for addressing and routing the data packets. iv. Network Interface – Defines how the host connects to the network.

3. What are well known ports? Also known as “reserve ports”, which are ports 1 – 1023 that are reserved by ICANN (Internet Corporation for Assigned Names and Numbers).

Port Number Assignments Port Numbers Description 1 - 1023 The “well known” ports 1024 – 49,151 Registered ports 49,152 – 65,535 Private Ports

5. Define the purpose of a connection oriented protocol. Give an example. i. Establishes the network connection, manages the data transfer, and terminates the connection. I. Connection Oriented Protocol – Establishes a network connection, manages the delivery of data, and terminates the connection. ii. The TCP (Transport Control Protocol) protocol within the TCP/IP transport layer. I. TCP protocol establishes a set of rules or guidelines for establishing the connection.

7. What is the purpose of a sequence number (SEQ=) in TCP data packets? SEQ (Sequence Number) is used to keep track of the data packets being transferred from Host A to Host B.

9. Describe how a TCP connection is terminated. i. The host sends a FIN (Finish) packet to the other connected host. 1. Host B sends a FIN packet to Host A indicating the data transmission is complete. 2. Host A responds with an ACK packet acknowledging the reception of the FIN packet. 3. Host A then sends Host B a FIN packet indicating that the connection is being terminated. 4. Host B replies with an ACK packet.

11. What is the purpose of the Internet layer in the TCP/IP protocol suite? i. It defines the protocols used for addressing and routing the data packets. I. Examples – IP, ARP, ICMP, & IGMP. 1. IP (Internet Protocol) – Defines the addressing used to identify the source and destination addresses of data packets being delivered over an IP network 2. ARP (Address Resolution Protocol) – Used to map an IP address to its MAC address. 3. ICMP (Internet Control Message Protocol) – Used to control the flow of data in the network, for reporting error, and for performing diagnostics. a. Contains “Ping” (packet Internet groper) troubleshooting tool. 4. IGMP (Internet Group Message Protocol) – Used when one host needs to send data to many destination hosts. a. This process is called Multicasting. b. Example - Streaming (audio and video) - data is sent without waiting for an acknowledgement that the data packets were delivered.

13. What is the purpose of an ARP reply? A reply from the host assigned the IP address replies with an ARP reply. ARP Reply - The protocol that contains the hardware address (MAC address) for the destination host that sent the ARP request.

15. When is IGMP used? IGMP is used when multicasting (when one host wants to send data to many destination hosts). The source doesn’t care whether the destination receives a packet.

17. Convert the following 8-bit binary number to decimal: 10010011? 147

19. Convert the following 8-bit number to decimal 11111100? 252

21. Convert the number 192 to its binary equivalent? 11000000

23. Convert the number 96 to its binary equivalent? 01100001

25. Convert 0x5AF3 to binary. Use Table 5-5. 0101101011110011

27. What is the IP address range for class C addresses? 192.0.0.0 – 223.255.255.255

29. How many bits are in an IPv4 address? How many octets? Bits – 32 Octets – 4 31. The IP address 192.168.12.2 is an example of what format? Dotted decimal format and is a Class C network.

33. How many network and host bits are in a class C network address? 24 Network bits and 8 Host Bits

35. Can private IP address be routed? No, They are Non- Internet Routable IP Addresses and not routed on the internet Non- Internet Routable IP Addresses - IP addresses not routed on the internet and are blocked by the ISP.

37. What organization assigns IP addresses? The ARIN (American Registry for Internet Numbers)
39. What is the purpose of a subnet mask? The subnet mask identifies what bits in the IP address are to be used to represent the network/subnet portion of an IP address.

41. The subnet mask 255.255.255.224 is applied to a packet with a destination IP address of 192.168.12.135. What subnet is the packet sent to? 192.168.12.128
43. Given an IP address of 193.10.10.0 answer the following questions if the number of subnets created is 4.
Network Address Broadcast Address
1st subnet 193.10.10.0 193.10.10.23
2nd subnet 193.10.10.64 193.10.10.27
3rd subnet 193.10.10.128 193.10.10.191
4th subnet 193.10.10.192 193.10.10.256

(b) Determine the subnet mask. _255____ . __255___ . __255___ . _192____
(c) Determine the number of usable hosts per subnet 62