Through protocol analyzers we are able to analyze the functioning of various protocols, and eliminating errors in the network ... The network is composed of many network elements through which several types of traffic travel around. Protocol analyzers are used to control the network, and by using them to capture the traffic we get the protocol analysis.
In thesis I have used a protocol analyzer named Wireshark in order to capture traffic on my local network, which has been connected with the outside world through the router of the service provider. I have covered and filtered the packets that belong to the basic communication protocols of TCP/IP world. I have completed a capturing of the DHCP packets, because I wanted to find out what IP address is assigned to my computer by the DHCP server. I have also captured two ARP packets and discovered the MAC address of my computer and router. I have repeated the experiment with a different service provider, because I wanted to find out if each network element indeed has its unique MAC address. With the next capturing of DNS packets I learned the web server address of the Faculty of Electrical Engineering. For comparison of unsecure and secure transmission of packets I did a comparison between HTTP and HTTPS, and proved that HTTPS uses an extra layer of protection for secure downloading content by using an encryption algorithm. In the ICMP packet capture, I received the access time of four packets that were successfully transferred.
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