Sliding Window
Explanation:
The Sliding Window protocol is a feature of packet-based data transmission protocols. It is used in the data link
layer (OSI model) as well as in TCP (transport layer of the OSI model). It is used to keep a record of the frame
sequences sent, and their respective acknowledgements received, by both the users. Its additional feature
over a simpler protocol is that can allow multiple packets to be "in transmission" simultaneously, rather than
waiting for each packet to be acknowledged before sending the next.In transmit flow control, sliding window is
a variable-duration window that allows a sender to transmit a specified number of data units before an
acknowledgment is received or before a specified event occurs.An example of a sliding window is one in
which, after the sender fails to receive an acknowledgment for the first transmitted frame, the sender "slides"
the window, i.e., resets the window, and sends a second frame. This process is repeated for the specified
number of times before the sender interrupts transmission. Sliding window is sometimes called
acknowledgment delay period.

Ettercap is a Unix and Windows tool for computer network protocol analysis and security auditing. It is capable of intercepting traffic on a network segment, capturing passwords, and conducting active eavesdropping against a number of common protocols. It is a free open source software. Ettercap supports active and passive dissection of many protocols (including ciphered ones) and provides many features for network and host analysis. Answer option C is incorrect. BackTrack is a Linux distribution distributed as a Live CD, which is used for penetration testing. It allows users to include customizable scripts, additional tools and configurable kernels in personalized distributions. It contains various tools, such as Metasploit integration, RFMON injection capable wireless drivers, kismet, autoscan-network (network discovering and managing application), nmap, ettercap, wireshark (formerly known as Ethereal). Answer option A is incorrect. AirSnort is a Linux-based WLAN WEP cracking tool that recovers encryption keys. AirSnort operates by passively monitoring transmissions. It uses Ciphertext Only Attack and captures approximately 5 to 10 million packets to decrypt the WEP keys. Answer option D is incorrect. Aircrack is the fastest WEP/WPA cracking tool used for 802.11a/b/g WEP and WPA cracking.

Adeona is a free laptop tracker that helps in tracking a user's laptop in case it gets stolen. All it takes is to
install the Adeona software client on the user's laptop, pick a password, and make it run in the background. If
at one point, the user's laptop gets stolen and is connected to the Internet, the Adeona software sends the
criminal's IP address. Using the Adeona Recovery, the IP address can then be retrieved. Knowing the IP
address helps in tracking the geographical location of the stolen device.
Answer option D is incorrect. Nessus is proprietary comprehensive vulnerability scanning software. It is free of
charge for personal use in a non-enterprise environment. Its goal is to detect potential vulnerabilities on tested
systems. It is capable of checking various types of vulnerabilities, some of which are as follows: Vulnerabilities
that allow a remote cracker to control or access sensitive data on a system Misconfiguration (e.g. open mail
relay, missing patches, etc), Default passwords, a few common passwords, and blank/absent passwords on
some system accounts. Nessus can also call Hydra (an external tool) to launch a dictionary attack. Denials of
service against the TCP/IP stack by using mangled packets
Answer option A is incorrect. SAINT stands for System Administrator's Integrated Network Tool. It is computer
software used for scanning computer networks for security vulnerabilities, and exploiting found vulnerabilities.
The SAINT scanner screens every live system on a network for TCP and UDP services. For each service it
finds running, it launches a set of probes designed to detect anything that could allow an attacker to gain
unauthorized access, create a denial-of-service, or gain sensitive information about the network.
Answer option C is incorrect. Snort is an open source network intrusion detection system. The Snort
application analyzes network traffic in realtime mode. It performs packet sniffing, packet logging, protocol
analysis, and a content search to detect a variety of potential attacks.