What is the main objective of Wireshark and discuss the use

What is the main objective of Wireshark and discuss the use of filters?

Discuss the manner in which the sequence and acknowledgement numbers are used during data transmission, in particular how they change, plus mention your own thoughts after seeing the video.

Solution

The main objective of Wireshark is to capture packets that are transmitted over a network. Wireshark can capture, decode and show various details of packets transmitted over a network. It can be used to capture packets of variety of protocols (e.g. ICMP, SNMP) and can be used for TCP and UDP data transmission. The main objectives are to capture data being transmitted, check for any protocol errors, examine security problems and debug network issues.

Filters in wireshark allows us to see only packets of a particular type or from a particular source or destination. Filters allow us to ckeck for packets based on a particular protocol, source IP/port, destination IP/port. It also helps us to capture packets from a particular subnet or a combination of any of the above criterias.

Sequence & acknowledgement numbers are used to detect any error in the transmission. The sender maintains a window of sequence number and the receiver keeps track of the acknowledgements send. The acknowlwdgements received by the sender indicates which packets are transmitted successfully. If acknowledgements arrive out of order, the sender would know that a packet loss has occured. Similarly, if the receiver receives packets with out of order sequence number, it knows that something wrong has happened. Based on this, any corrective action can be taken by the sender. There are several different protocols that use sequence & acknowledgement for error detection.