Snort is a free and open source Network Intrusion Detection System (NIDS) software that can run on a variety of operating systems, including Linux, UNIX, Windows, etc.
Snort has the following technical principles:
Packet capture: Snort captures network packets through network interfaces or pcap files.
Packet parsing: Snort parses the captured data packets and extracts the information required by the network protocol.
Rule matching: Snort performs rule matching on each data packet. If the match is successful, it means that there is a security threat in the data packet.
Logging: Snort records the matched data packets into the log, and can record different levels of log information according to different rules.
The main role of Snort is to detect network intrusions. It can identify and record various network attacks, such as DoS attacks, scanning, port scanning, sniffing, and information disclosure. Once an intrusion is detected, Snort will immediately notify the administrator or security team so that they can take appropriate measures to deal with it.
The use of Snort includes the following steps:
Installation: Download the software installation package and install the Snort software.
Configuration: edit the Snort configuration file, and set parameters such as network interface, rule path, and log.
Download rules: download the latest rule files from Snort official website or third-party website.
Start: Run the Snort software, enter commands in the terminal, and start Snort.
Monitor network traffic: Snort will monitor network traffic on the specified network interface and match it according to the rules.
Handle alerts: Once a security threat is found, Snort will send alert information to the administrator, and the administrator can take corresponding measures to deal with it.
Snort works in two ways:
signature detection mode
The signature detection mode is also called the rule-based detection mode, which is the most commonly used detection method of Snort. It detects and analyzes network communication data in real time based on a preset rule base or user-defined rules. The rule base contains a series of detection rules, and each rule includes the matching part and the action that needs to be taken when a threat is found through the rule, such as alerting, dropping data packets, and calling other programs. Snort parses and analyzes the data packets, and matches each received data packet according to the pre-defined rules. Once the matching is successful, it will report the alarm information.
traffic analysis mode
Traffic analysis mode, also known as traffic analysis-based detection mode, uses traffic analysis techniques to detect abnormal network traffic. Snort defines and manages traffic. It does not detect traffic according to specific rules, but detects whether traffic is abnormal by analyzing traffic behavior, duration, and the relationship between data packets. For example, when it detects that data packets are sent frequently and repeatedly, Snort will consider this as a DoS attack, and then send out an alarm message.
In addition to being an intrusion detection system (NIDS), Snort also has a certain network audit function , which can audit network traffic and generate specific log records, so as to help administrators or security specialists understand the usage and security status of the network.
Some of Snort's auditing capabilities include:
Traffic statistics: Snort can count the traffic of different protocols, the traffic of users or devices, and the traffic of remote hosts and services.
IP address and port number statistics: Snort can count the number of data packets for each IP address and port number, as well as their source and destination traffic conditions.
Traffic capture: Snort can capture all data packets transmitted by the network and record them.
Traffic tracking: Snort can track the network traffic of a specific user, port or protocol and perform record analysis, such as HTTP request analysis, SMTP mail tracking and FTP file transfer.
Through the above audit functions, Snort can monitor and audit network traffic in detail, so that administrators can understand network usage and emergency response, thereby improving network security.
Sniffer (sniffer) is a network security tool that can capture and analyze network data packets in real time to help system administrators and network security experts analyze events occurring in the network, find network problems and deal with security threats. Common usage scenarios of Sniffer include network monitoring, debugging, and security auditing.
Different from Snort, Sniffer is mainly used for network traffic analysis and monitoring, rather than intrusion detection . Sniffer can be installed on a computer or an embedded device in order to realize sniffing and analysis of different network devices.
Using Sniffer generally includes the following steps:
Installation and configuration: select the appropriate Sniffer tool, and install and configure it.
Capture packets: start Sniffer, start to capture network packets and save them into PCAP files.
Data packet analysis: use professional data packet analysis tools, such as Wireshark, to analyze and decode captured data packets in order to understand the information transmitted in network traffic.
Dealing with problems and threats: Identify network problems and threats based on the analysis results, and take corresponding measures to deal with them.
Sniffer includes hardware and software types, among which software type sniffer includes:
NetXRay is a commercial network sniffer with advanced network sniffing and analysis capabilities. It has a user-friendly graphical user interface, which can capture and map the flow of network packets in real time, and also provides deep network and application layer protocol decoding, traffic detection and filtering, and various analysis tools. NetXRay supports multiple operating system platforms, including Windows, Mac OS X and Linux, and can receive data packets of various protocols, such as IP, TCP, UDP, ICMP, etc. At the same time, it also supports in-depth decoding of application layer protocols such as SSL/TLS, SSH, HTTP, POP3, IMAP, LDAP, etc., and can analyze complex network protocols. In addition, NetXRay also provides real-time statistics and reporting functions, which can monitor and audit network traffic and performance. Users can export and share statistical data to facilitate analysis and communication.
Packetboy is a commercial network analysis tool that helps businesses and organizations monitor and analyze network traffic. Packetboy provides an intuitive web interface that allows users to quickly view network data and events. It can decode and analyze various protocols including TCP/IP, HTTP, SMTP, FTP, etc. Packetboy can capture network traffic and generate analysis reports to ensure network security. It also provides automated network tools such as IP blacklisting, traffic monitoring, and unusual activity detection to help prevent security threats such as intrusions and data leaks. In addition, Packetboy also provides complete logging, allowing users to check historical data at any time. You can also monitor the statistics of network traffic in real time to quickly locate losses and bottlenecks and help improve network performance.
NetMonitor is a powerful commercial network monitoring tool that can be used to monitor, analyze, diagnose, optimize and debug network devices and applications. NetMonitor supports multiple operating systems and network architectures, including Windows, Linux, Cisco IOS, etc. NetMonitor can capture data packets and display real-time network traffic, as well as perform detailed analysis on data packets. It supports multiple protocols, including TCP/IP, HTTP, DNS, LDAP, etc. Users can use NetMonitor to diagnose network faults and performance bottlenecks, find abnormal network traffic, monitor network security and other issues.
WinPcap is an open source network sniffing library that can be used by many network monitoring and analysis tools. WinPcap provides an API and drivers on your computer to capture and analyze network packets on the Windows operating system. WinPcap can be used on Windows 98, ME, 2000, XP, Server 2003, Vista, Server 2008, Windows 7 and Windows 8, it supports a variety of network protocols and packet formats, such as Ethernet, IP, TCP, UDP, ICMP, etc. . WinPcap can capture and record network packets, at the same time it can decode network protocols and provide traffic statistics. Since WinPcap is an open source network sniffing library, it is also used by many developers to write network monitoring and security tools, such as Wireshark and Nmap.
Wireshark is a cross-platform network protocol analyzer that can decode and analyze multiple protocols and supports multiple operating system platforms, such as Windows, Linux and Mac OS X.
The hardware type sniffer mainly refers to a network analyzer (Network Analyzer) or a protocol analyzer (Protocol Analyzer), which is a professional network traffic analysis device that supports capturing and analyzing various network protocols and data packets. The following are some common hardware types of sniffer products:
Fluke Networks can provide a variety of testing tools such as link analyzers and network traffic analyzers, which can conduct in-depth analysis and debugging of network traffic.
Riverbed provides network optimization and traffic analysis functions through a variety of hardware appliances, including products such as SteelCentral Packet Analyzer and SteelCentral AppResponse.
Netscout produces a variety of hardware network traffic analysis equipment, including products such as nGeniusONE and InfiniStream, which can conduct comprehensive analysis and optimization of the network.
Colasoft is also a professional provider of network analysis and security software, which provides combined hardware and software solutions, including Capsa Network Analyzer, CapMaker and other products.