As the ack number 1 thus the server knows to which

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as the ACK number + 1. Thus, the server knows to which TCP connection the client is referring to and closes the connection.
3. A TCP connection is full duplex. At this state, the connection is half closed. The next step is for the client to send a FIN ACK packet to the server and the server responds with an ACK packet which closes the client side of the connection. Notice again how TCP copies the SEQ number of the FIN ACK packet as the SEQ number of the ACK packet and the ACK number is the SEQ number of the FIN ACK packet + 1.
Lab 3 DCF255 P a g e | 5 ARP Protocol 1. The ARP protocol is used to map IP addresses to Ethernet addresses which is used on a LAN. Since we deleted the ARP cache the default gateway physical address is not in the ARP cache, so ARP broadcasts to all hosts on the network, “whoever owns this IP address, please forward to me your MAC address” so I can send you some data. Notice it is the Internet layer that gets the physical or MAC address, which is added to the Data Link header. ARP proves that messages are forwarded link-by-link from source to destination. 2. Click on the first ARP packet. 3. Observe the details pane. Notice that the packet is encapsulated inside an Ethernet frame. Answer the following questions and complete the table below. ARP Request Packet What type of ARP packet is this? Client FIN ACK ACK FIN ACK ACK Half closed y closed Server
What is the destination physical address of
the ARP packet? What type of casting is this address?
What is the source physical address of the
ARP packet? What is the sender’s IP address?
What is the target’s IP address?
4. Scroll down to the next ARP packet Click on the packet and observer the details pane. Answer the following questions: ARP Reply Packet What type of ARP packet is this?
What is the destination physical address of
the ARP packet? What type of casting is this address?
Lab 3 DCF255 P a g e | 6 What is the source physical address of the
ARP packet? What is the sender’s IP address?
What is the target’s IP address?
Other Common Protocols Scroll through the list of protocols listed in Wireshark and identify 4 additional protocols. Provide a one sentence description of the protocol’s purpose. (use your own words, do not copy and paste) Protocol Description SSDP Packet for discovery of network services and presence information TLSv1.2 Encryption for web services UDP Get a datagram from one computer to another SNMP Packet that contains header, data and checksum Grading: DCF255_L3_packetcapture .docx – with completed tables LearnName_L3_packetcapture.pcap Upload files using link on MySeneca\Graded Work
Lab 3 DCF255 P a g e | 7

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