Usually in servers, there is no graphical environment installed and with that you cannot use WireShark directly.

Just to let you change the filter and examine the contents of the connection. This can be transported to any connection in plain text, such as FTP, Telnet, HTTP, etc. After you create your filter, just click 'Apply', if you wanted to see the entire list of packages again just click 'Clear', this will remove the filter previously applied. The filters can be constructed by clicking on 'Filter', then selecting the desired filter (there is a short list of pre-defined filters), or by typing directly into the text box. There are a plethora of possible filters, but at this moment we will see just how to filter by IP address, port and protocol.

The next step is to identify what interests among many packages. With this we have the basics of the program, we can set the capture interface, start and stop the capture. The greater the amount of packets, the longer it takes to apply a filter, find a package, etc. It is important to remember that you must take care if your network is busy, the data stream may even lock your machine, then it is not advisable to leave the WireShark to capture for a long time, as we will see, we will leave it running only during the process to debug a connection.

Generally the data is organized by type of protocol (TCP, UDP, FTP, ICMP, etc.) and each package read may have show your content. If a sniffer were running on other computers, even without these systems sending data it travels there for the operating system, the sniffer will intercept at the network layer, capturing the data and displaying them to the user, in an unfriendly way. It turns out that only the machine on which the information was intended to send the operating system. When we called the HUB computer and send information from one computer to another, in reality this data is for all ports of the HUB, and therefore for all machines. Always aimed at getting the most relevant information. These programs aim at monitoring ('sniffing') network traffic to capture access to network services, such as remote mail service (IMAP, POP3), remote access (telnet, rlogin, etc.), file transfer (FTP) etc.

These programs also allow you to monitor network activity recording data (usernames, passwords ect.) each time they access other computers on the network. They are used for network analysis purposes, however they can also be used by malicious hackers to capture your passwords, and even IDS systems are based on network sniffers. What are 'sniffers'? The main purpose of a sniffer is to capture network traffic.

Wireshark captures passwords