While focusing on network security monitoring, Bro provides a comprehensive platform for more general network traffic analysis as well. Well grounded in more than 15 years of research, Bro has successfully bridged the traditional gap between academia and operations since its inception. Today, it is relied upon operationally in particular by many scientific environments for securing their cyberinfrastructure. Bro’s user community includes major universities, research labs, supercomputing centers, and open-science communities.
Bro is a passive, open-source network traffic analyzer. It is primarily a security monitor that inspects all traffic on a link in depth for signs of suspicious activity. More generally, however, Bro supports a wide range of traffic analysis tasks even outside of the security domain, including performance measurements and helping with trouble-shooting.
Features
- Deployment
- Runs on commodity hardware on standard UNIX-style systems (including Linux, FreeBSD, and MacOS).
- Fully passive traffic analysis off a network tap or monitoring port.
- Standard libpcap interface for capturing packets.
- Real-time and offline analysis.
- Cluster-support for large-scale deployments.
- Unified management framework for operating both standalone and cluster setups.
- Open-source under a BSD license.
- Analysis
- Comprehensive logging of activity for offline analysis and forensics.
- Port-independent analysis of application-layer protocols.
- Support for many application-layer protocols (including DNS, FTP, HTTP, IRC, SMTP, SSH, SSL).
- Analysis of file content exchanged over application-layer protocols, including MD5/SHA1 computation for fingerprinting.
- Comprehensive IPv6 support.
- Tunnel detection and analysis (including Ayiya, Teredo, GTPv1). Bro decapsulates the tunnels and then proceeds to analyze their content as if no tunnel was in place.
- Extensive sanity checks during protocol analysis.
- Support for IDS-style pattern matching.
- Scripting Language
- Turing-complete language for expression arbitrary analysis tasks.
- Event-based programming model.
- Domain-specific data types such as IP addresses (transparently handling both IPv4 and IPv6), port numbers, and timers.
- Extensive support for tracking and managing network state over time.
- Interfacing
- Default output to well-structured ASCII logs.
- Alternative backends for ElasticSearch and DataSeries. Further database interfaces in preparation.
- Real-time integration of external input into analyses. Live database input in preparation.
- External C library for exchanging Bro events with external programs. Comes with Perl, Python, and Ruby bindings.
- Ability to trigger arbitrary external processes from within the scripting language.
