Provide a description of how Telnet and FTP work. What is common between these protocols?
How Telnet Works
Telnet is a software-based mode of communication that is used to connect a client and a remote host (server). The software is normally installed on the client computer and when the user wants to connect to the server, he sends a request via the client software to the server. The server in turn asks for authentication information from the client and when verified, a connection is established. This enables the client to access the host’s resources virtually. The client acts as a virtual office.
Authentication is basically by use of username and password which are set when a user account is created on the client. The legitimate user in this case can access all files on the host and work on them as if he was physically present. Limited access can however be granted to visitors who can log on to the system without the basic authentication (Forouzan 2000).
How FTP works
In FTP, users can access information on the server through the internet or Intranet based communication channel. FTP is mainly used where files need to be transferred to and from a central storage location. The users on their client computers access a server which is a computer on which data, information, and control programs are stored by sending requests as per their requirements to the server.
When a connect request is received by the host, the client is asked to provide a username and password to verify their identity and when verified as legitimate users, two connections are established; a control channel through which control signals are relayed and a data channel used for data transfer (Forouzan 2000). The control channel stays open throughout the session while the data channel opens and closes as the need arises. The level of access is controlled by the assignment of user rights by the system administrator.
Comparison between Telnet & FTP
Both Telnet and FTP enable communication between two computers in a client-server model and they are software-based. Both lack built-in security measures and are therefore vulnerable to attacks but newer versions have been developed to incorporate security measures such as FTPS and SFTP and SSH in place of Telnet.. Both FTP and Telnet employ the use of command line, FTP has features that enable its use with a dedicated application and most file browsers.
FTP is mainly used in file transfers between two communicating computers while Telnet is used to issue commands to a remote host. Telnet allows remote access to a user account on the server, while FTP allows general file access.
Provide a description of how Ethereal can be used to study traffic and what can be achieved with Ethereal?
Ethereal has special features that allow it to view packets on the network. Its ability to read files capture by other filters makes it very useful when it comes to analyzing the kind of traffic flowing in a network. In addition, its filtering capability finds application in keeping off spam from the network; this is made even easier by the fact that its source code is freely available hence a user can customize it to meet his particular requirements.
The use of ethereal as a sniffing tool on a network can minimize cyberspace intrusion attempts as most of the malicious or unwanted packets are kept off the network. Ethereal is compatible with Windows, Linux, and Unix operating systems and thus it can be widely used, (Ethereal: the world’s most popular network protocol analyzer 2006).
References
Ethereal: the world’s most popular network protocol analyzer 2006. Web.
Forouzan, B. 2000. TCP/IP: Protocol Suite. 1st Ed. Tata McGraw-Hill Publishing Company, New Delhi India.