Abstract—While analyzing CAIDA Internet traces of TCP traffic to detect instances of data reneging, we frequently observed four misbehaviors in the generation of SACKs. These misbehaviors could result in the data sender mistakenly thinking data reneging occurred. Further testing detected two additional SACK generation misbehaviors which in the worst case could result in a data sender receiving a SACK for data that was never received. This paper reports the results of testing a wide range of operating systems using TBIT to document which ones misbehave in each of the six ways. One can conclude that the handling of SACKs while simple in concept is complex to implement.
Keywords- SACK; Selective Acknowledgement; TCP; TBIT
I. INTRODUCTION
The Selective Acknowledgment (SACK) mechanism, RFC 2018 [1], an extension to Transmission Control Protocol’s (TCP) [2] ACK mechanism, allows a data receiver to explicitly acknowledge arrived out-of-order data to the data sender. When using SACKs, a TCP data sender need not retransmit SACKed data during the loss recovery period. Previous research [3...
Lab 1 demonstrates the capabilities of congestion control algorithms implemented by Transmission Control Protocol (TCP). It provides three scenarios to simulate these algorithms and will later compare the results.
The Operating System (OS) is the heart of computer server and client systems; therefore they are the pivotal components of the Information Technology (IT) architecture. The OS contains the crucial data, information, and applications, which are vulnerable, and can be infiltrated to cripple the entire IT architecture of the organization. Therefore, it becomes mandatory to properly safeguard the OS from an internal or external intrusion (Stallings & Brown, 2012). This critical thinking report will highlight the security concerns that may impact the OS. Further, the security guidelines and best practices for the OS in general, along with the specific fundamentals regarding the Windows and Linux OS are comprehensively illustrated.
In order to prevent both intentional and unintentional alteration, and destruction of information, any software application needs controls to ensure the reliability of data. Here are two specific controls per each one of the three data control categories, and how each control contributes to ensuring the data reliability in the format requested.
Blackhole attack is another type of DoS attack that generates and disseminates build routing information. As mentioned in [20], a attacker, exploiting the flooding based routing protocol, advertises itself as having a valid shortest route to the destined node. If the atacker replies to the requesting node before the actual node replies, a bogus route will be created. Hence packets are not forwarded to the certain destination node; instead, the attacker intercepts the packets, drops them and thus, attracts network traffic [21].
In the movie Regarding Henry, Henry Turner (Harrison Ford) is shot in the head twice when he walked into a convenience store while it was being robbed. He wakes up from a coma and has apparently lost all of his memory. After the accident he is pretty much like a child learning everything all over again. He doesn’t remember his friends, coworkers, or even who his family are and what roles they play in his life and in his family.
Nowadays, most of the web, email, database and fileservers are Linux servers. Linux is a UNIX system which implies that it has solid compatibility, stability and security features. Linux is used for the mentioned environments because these services require high security. Further, an increase of attacks on these servers can be observed. Additionally, the methods to prevent intrusions on Linux machines are insufficient. Further, the analysis of incidents on Linux systems are not considered appropriately (Choi, Savoldi, Gubian, Lee, & Lee, 2008). It can also be observed that a lot of investigators do not have experience with Linux forensics (Altheide, 2004).
* SmartStream(tm) automatically resumes broken content streams by finding another source for the same content and monitoring the network until the requested content stream becomes available
Beilock, Sian. How the Body Knows Its Mind. New York, NY: Atria Books, 2015. Print. (152-158)
TOR (Roger Dingledine) is a circuit based low-latency anonymous communication service. TOR is now in its second generation and was developed from the Onion routing program. The routing system can run on several operating systems and protect the anonymity of the user. The latest TOR version supports perfect forward secrecy, congestion control, directory servers, integrity checking and configurable exit policies. Tor is essentially a distributed overlay network which works on the application layer of the TCP protocol. It essentially anonymizes all TCP-based applications like web-browsing, SSH, instant messaging. Using TOR can protect against common form of Internet surveillance known as “traffic analysis” (Electronic Frontier Foundation). Knowing the source and destination of your internet traffic allows others to track your behavior and interests. An IP packet has a header and a dat...
Summary Report for: Computer Security. (2010). January 10, 2011, from O*net Online: retreived January/15/2011 http://online.onetcenter.org/link/summary/15-1071.01
Recently C++ has made its way into the Internet community. For over ten years, business’ have used C++ for their Internet needs, for example, sending and receiving important data pertaining to their business across the Internet and allowing it to quickly and safely reach the other end of communication and all in one piece. With the high demands of today’s Internet users, whether it be an online shopper or one that desires to seek information on a certain topic, it is essential that the information can be sent from the user, to the server, and then back again as swiftly as possible and with utmost dependability… all, of course, without the loss of security.
... congestion collapse are solved by timer improvements and congestion control mechanism in modern implementations of TCP.
Everyday people use social cognition as a tool to help them thrive in social world. There are many important aspects of social cognition that are helpful to us in making decisions and help us to interpret the world around us. An important aspect that is linked to social cognition is that of thought suppression. Thought suppression is when a person tries to force particular thoughts, memories or feelings out of their minds that may be unpleasant or may cause a great deal of stress for the individual. Many people are unaware how often we use thought suppression in our daily lives, but the truth is we use it in almost every aspect of our day.
Why is one man sad and another man happy? Why is one man fearful and anxious and another full of faith and confidence? Why is one man a great success and other an abject failure? Why is one man healed of so called disease and another isn’t?
The goal of this paper is to define and explore the MD5 checksum utility. It is also my goal to discuss how to use MD5 checksums to support Incident Response.