In computing, traceroute and tracert are computer network diagnostic commands for displaying possible routes (paths) and measuring transit delays of packets across an Internet Protocol (IP) network. The history of the route is recorded as the round-trip times of the packets received from each successive host in the route (path); the sum of the mean times in each hop is a measure of the total time spent to establish the connection. Traceroute proceeds unless all sent packets are lost more than twice; then the connection is lost and the route cannot be evaluated. Ping, on the other hand, only computes the final round-trip times from the destination point.
Unix security refers to the means of securing a Unix or Unix-like operating system. A secure environment is achieved not only by the design concepts of these operating systems, but also through vigilant user and administrative practices.
A home directory is a file system directory on a multi-user operating system containing files for a given user of the system. The specifics of the home directory are defined by the operating system involved; for example, Linux / BSD (FHS) systems use /home/⟨username⟩ or /usr/home/⟨username⟩ and Windows systems between 2000 and Server 2003 keep home directories in a folder named Documents and Settings.
PF is a BSD licensed stateful packet filter, a central piece of software for firewalling. It is comparable to netfilter (iptables), ipfw, and ipfilter.
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.
sudo is a program for Unix-like computer operating systems that enables users to run programs with the security privileges of another user, by default the superuser. It originally stood for "superuser do", as that was all it did, and it is its most common usage; however, the official Sudo project page lists it as "su 'do' ". The current Linux manual pages for su define it as "substitute user", making the correct meaning of sudo "substitute user, do", because sudo can run a command as other users as well.
Kismet is a network detector, packet sniffer, and intrusion detection system for 802.11 wireless LANs. Kismet will work with any wireless card which supports raw monitoring mode, and can sniff 802.11a, 802.11b, 802.11g, and 802.11n traffic. The program runs under Linux, FreeBSD, NetBSD, OpenBSD, and macOS. The client can also run on Microsoft Windows, although, aside from external drones, there's only one supported wireless hardware available as packet source.
In the field of computer network administration, pcap is an application programming interface (API) for capturing network traffic. While the name is an abbreviation of packet capture, that is not the API's proper name. Unix-like systems implement pcap in the libpcap library; for Windows, there is a port of libpcap named WinPcap that is no longer supported or developed, and a port named Npcap for Windows 7 and later that is still supported.
Monitor mode, or RFMON mode, allows a computer with a wireless network interface controller (WNIC) to monitor all traffic received on a wireless channel. Unlike promiscuous mode, which is also used for packet sniffing, monitor mode allows packets to be captured without having to associate with an access point or ad hoc network first. Monitor mode only applies to wireless networks, while promiscuous mode can be used on both wired and wireless networks. Monitor mode is one of the eight modes that 802.11 wireless adapter can operate in: Master, Managed, Ad hoc, Repeater, Mesh, Wi-Fi Direct, TDLS and Monitor mode.
Netlink is a socket family used for inter-process communication (IPC) between both the kernel and userspace processes, and between different userspace processes, in a way similar to the Unix domain sockets available on certain Unix-like operating systems, including its original incarnation as a Linux kernel interface, as well as in the form of a later implementation on FreeBSD. Similarly to the Unix domain sockets, and unlike INET sockets, Netlink communication cannot traverse host boundaries. However, while the Unix domain sockets use the file system namespace, Netlink sockets are usually addressed by process identifiers (PIDs).
In Unix-like operating systems, a loop device, vnd, or lofi is a pseudo-device that makes a computer file accessible as a block device.
Wireshark is a free and open-source packet analyzer. It is used for network troubleshooting, analysis, software and communications protocol development, and education. Originally named Ethereal, the project was renamed Wireshark in May 2006 due to trademark issues.
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.
EtherApe is a packet sniffer/network traffic monitoring tool, developed for Unix. EtherApe is free, open source software developed under the GNU General Public License.
Bit-Twist is a libpcap-based packet generator and packet capture file modifier and replayer. It complements tcpdump, a packet capturing tool also built upon the packet capturing engine libpcap. Bit-Twist allows you to regenerate packets from one or more pcap files. It also comes with a comprehensive pcap file editor to allow advance manipulation of packet information, e.g. fields in Ethernet, ARP, IP, ICMP, TCP, and UDP headers, prior to regenerating the packets onto the network.
ngrep is a network packet analyzer written by Jordan Ritter. It has a command-line interface, and relies upon the pcap library and the GNU regex library.
Justniffer is a TCP packet sniffer. It can log network traffic in a 'standard' or in a customized way. It can also log response times, useful for tracking network services performances . The output format of the traffic can be easily customized. An example written in Python stores the transferred contents in an output directory separated by domains. This means that the transferred files like html, css, javascript, images, sounds, etc. can be saved to a directory.
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, 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.
Xplico is a network forensics analysis tool (NFAT), which is a software that reconstructs the contents of acquisitions performed with a packet sniffer.
The Logitech Unifying receiver is a small dedicated USB wireless receiver, based on the nRF24L-family of RF devices, that allows up to six compatible Logitech human interface devices to be linked to the same computer using 2.4 GHz band radio communication. Receivers that are bundled with a Logitech product are paired with the device at the factory. When purchasing a replacement receiver or connecting multiple devices to one receiver, pairing requires the free-of-charge Logitech Unifying software, available for Microsoft Windows and Mac OS X. On Linux the Solaar software can be used to adjust the configurations. Although not compatible with Bluetooth, devices pair to Unifying Receivers in a similar way. Peripherals remain paired, and can then be used on systems not supporting the software. Logitech receivers compatible with the Unifying protocol can be identified by the orange Unifying logo, which distinguishes them from Logitech Nano receivers of similar appearance, which pair in a similar manner but only with a single device, without using the Unifying protocol.
