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Netsniff-ng
netsniff-ng is a free Linux network analyzer and networking toolkit originally written by Daniel Borkmann. Its gain of performance is reached by zero-copy mechanisms for network packets (RX_RING, TX_RING), so that the Linux kernel does not need to copy packets from kernel space to user space via system calls such as recvmsg(). libpcap, starting with release 1.0.0, also supports the zero-copy mechanism on Linux for capturing (RX_RING), so programs using libpcap also use that mechanism on Linux. Overview netsniff-ng was initially created as a network sniffer with support of the Linux kernel packet- mmap interface for network packets, but later on, more tools have been added to make it a useful toolkit such as the iproute2 suite, for instance. Through the kernel's zero-copy interface, efficient packet processing can be reached even on commodity hardware. For instance, Gigabit Ethernet wire-speed has been reached with netsniff-ng's trafgen. The netsniff-ng toolkit does not depend o ...
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Mausezahn
(, German for "mouse tooth") is a fast network traffic generator written in C which allows the user to craft nearly every possible and "impossible" packet. Since version 0.31 Mausezahn is open source in terms of the GPLv2. Herbert Haas, the original developer of Mausezahn, died on 25 June 2011. The project has been incorporated into the netsniff-ng toolkit, and continues to be developed there. Typical applications of Mausezahn include: * Testing or stressing IP multicast networks * Penetration testing of firewalls and IDS * Finding weaknesses in network software or appliances * Creation of malformed packets to verify whether a system processes a given protocol correctly * Didactical demonstrations as lab utility Mausezahn allows sending an arbitrary sequence of bytes directly out of the network interface card. An integrated packet builder provides a simple command line interface for more complicated packets. Since version 0.38, Mausezahn offers a multi-threaded mode with Cisco ...
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Autonomous System (Internet)
An autonomous system (AS) is a collection of connected Internet Protocol (IP) routing prefixes under the control of one or more network operators on behalf of a single administrative entity or domain, that presents a common and clearly defined routing policy to the Internet. Each AS is assigned an autonomous system number (ASN), for use in Border Gateway Protocol (BGP) routing. Autonomous System Numbers are assigned to Local Internet Registries (LIRs) and end user organizations by their respective Regional Internet Registries (RIRs), which in turn receive blocks of ASNs for reassignment from the Internet Assigned Numbers Authority (IANA). The IANA also maintains a registry of ASNs which are reserved for private use (and should therefore not be announced to the global Internet). Originally, the definition required control by a single entity, typically an Internet service provider (ISP) or a very large organization with independent connections to multiple networks, that adhered t ...
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Berkeley Packet Filter
The Berkeley Packet Filter (BPF) is a technology used in certain computer operating systems for programs that need to, among other things, analyze network traffic. It provides a raw interface to data link layers, permitting raw link-layer packets to be sent and received. In addition, if the driver for the network interface supports promiscuous mode, it allows the interface to be put into that mode so that all packets on the network can be received, even those destined to other hosts. BPF supports filtering packets, allowing a userspace process to supply a filter program that specifies which packets it wants to receive. For example, a tcpdump process may want to receive only packets that initiate a TCP connection. BPF returns only packets that pass the filter that the process supplies. This avoids copying unwanted packets from the operating system kernel to the process, greatly improving performance. The filter program is in the form of instructions for a virtual machine, which are ...
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Zero-copy
"Zero-copy" describes computer operations in which the CPU does not perform the task of copying data from one memory area to another or in which unnecessary data copies are avoided. This is frequently used to save CPU cycles and memory bandwidth in many time consuming tasks, such as when transmitting a file at high speed over a network, etc., thus improving performances of programs ( processes) executed by a computer. Principle Zero-copy programming techniques can be used when exchanging data within a user space process (i.e. between two or more threads, etc.) and/or between two or more processes (see also producer–consumer problem) and/or when data has to be accessed / copied / moved inside kernel space or between a user space process and kernel space portions of operating systems (OS). Usually when a user space process has to execute system operations like reading or writing data from/to a device (i.e. a disk, a NIC, etc.) through their high level software inter ...
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Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which includes the kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name "GNU/Linux" to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian, Fedora Linux, and Ubuntu, the latter of which itself consists of many different distributions and modifications, including Lubuntu and Xubuntu. Commercial distributions include Red Hat Enterprise Linux and SUSE Linux Enterprise. Desktop Linux distributions include a windowing system such as X11 or Wayland, and a desktop environment such as GNOME or KDE Plasma. Distributions inten ...
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Gigabit Ethernet
In computer networking, Gigabit Ethernet (GbE or 1 GigE) is the term applied to transmitting Ethernet frames at a rate of a gigabit per second. The most popular variant, 1000BASE-T, is defined by the IEEE 802.3ab standard. It came into use in 1999, and has replaced Fast Ethernet in wired local networks due to its considerable speed improvement over Fast Ethernet, as well as its use of cables and equipment that are widely available, economical, and similar to previous standards. History Ethernet was the result of research conducted at Xerox PARC in the early 1970s, and later evolved into a widely implemented physical and link layer protocol. Fast Ethernet increased the speed from 10 to 100 megabits per second (Mbit/s). Gigabit Ethernet was the next iteration, increasing the speed to 1000 Mbit/s. * The initial standard for Gigabit Ethernet was produced by the IEEE in June 1998 as IEEE 802.3z, and required optical fiber. 802.3z is commonly referred to as 1000BASE-X, w ...
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Debian
Debian (), also known as Debian GNU/Linux, is a Linux distribution composed of free and open-source software, developed by the community-supported Debian Project, which was established by Ian Murdock on August 16, 1993. The first version of Debian (0.01) was released on September 15, 1993, and its first stable version (1.1) was released on June 17, 1996. The Debian Stable branch is the most popular edition for personal computers and servers. Debian is also the basis for many other distributions, most notably Ubuntu. Debian is one of the oldest operating systems based on the Linux kernel. The project is coordinated over the Internet by a team of volunteers guided by the Debian Project Leader and three foundational documents: the Debian Social Contract, the Debian Constitution, and the Debian Free Software Guidelines. New distributions are updated continually, and the next candidate is released after a time-based freeze. Since its founding, Debian has been developed openly a ...
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Elliptic-curve Cryptography
Elliptic-curve cryptography (ECC) is an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields. ECC allows smaller keys compared to non-EC cryptography (based on plain Galois fields) to provide equivalent security.Commercial National Security Algorithm Suite and Quantum Computing FAQ
U.S. National Security Agency, January 2016.
Elliptic curves are applicable for , s,
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IP Tunnel
An IP tunnel is an Internet Protocol (IP) network communications channel between two networks. It is used to transport another network protocol by encapsulation of its packets. IP tunnels are often used for connecting two disjoint IP networks that don't have a native routing path to each other, via an underlying routable protocol across an intermediate transport network. In conjunction with the IPsec protocol they may be used to create a virtual private network between two or more private networks across a public network such as the Internet. Another prominent use is to connect islands of IPv6 installations across the IPv4 Internet. In IP tunnelling, every IP packet, including addressing information of its source and destination IP networks, is encapsulated within another packet format native to the transit network. At the borders between the source network and the transit network, as well as the transit network and the destination network, gateways are used that establish ...
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Netfilter
Netfilter is a framework provided by the Linux kernel that allows various networking-related operations to be implemented in the form of customized handlers. Netfilter offers various functions and operations for packet filtering, network address translation, and port translation, which provide the functionality required for directing packets through a network and prohibiting packets from reaching sensitive locations within a network. Netfilter represents a set of hooks inside the Linux kernel, allowing specific kernel modules to register callback functions with the kernel's networking stack. Those functions, usually applied to the traffic in the form of filtering and modification rules, are called for every packet that traverses the respective hook within the networking stack. History Rusty Russell started the ''netfilter/iptables project'' in 1998; he had also authored the project's predecessor, ipchains. As the project grew, he founded the ''Netfilter Core Team'' (or ...
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Virtual Private Network
A virtual private network (VPN) extends a private network across a public network and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network. The benefits of a VPN include increases in functionality, security, and management of the private network. It provides access to resources that are inaccessible on the public network and is typically used for remote workers. Encryption is common, although not an inherent part of a VPN connection. A VPN is created by establishing a virtual point-to-point connection through the use of dedicated circuits or with tunneling protocols over existing networks. A VPN available from the public Internet can provide some of the benefits of a wide area network (WAN). From a user perspective, the resources available within the private network can be accessed remotely. Types Virtual private networks may be classified into several categories: ;Remote a ...
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Internet Protocol
The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet. IP has the task of delivering packets from the source host to the destination host solely based on the IP addresses in the packet headers. For this purpose, IP defines packet structures that encapsulate the data to be delivered. It also defines addressing methods that are used to label the datagram with source and destination information. IP was the connectionless datagram service in the original Transmission Control Program introduced by Vint Cerf and Bob Kahn in 1974, which was complemented by a connection-oriented service that became the basis for the Transmission Control Protocol (TCP). The Internet protocol suite is therefore often referred to as ''TCP/IP''. The first major version of IP, Internet Protocol Version 4 (IPv4), i ...
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