Syslog
Syslog is a standard for logging program messages. It allows separation of the software that generates messages from the system that stores them and the software that reports and analyzes them. It also provides devices which would otherwise be unable to communicate a means to notify administrators of problems or performance.
Syslog can be used for computer system management and security auditing as well as generalized informational, analysis, and debugging messages. It is supported by a wide variety of devices (like printers and routers) and receivers across multiple platforms. Because of this, syslog can be used to integrate log data from many different types of systems into a central repository.
Messages refer to a facility (auth, authpriv, daemon, cron, ftp, lpr, kern, mail, news, syslog, user, uucp, local0, ... , local7
) and are assigned a priority/level (Emergency, Alert, Critical, Error, Warning, Notice, Info
or Debug
)
by the sender of the message.
Configuration allows directing messages to various local devices (console), files (/var/log/) or remote syslog daemons. Care must be taken when updating the configuration as omitting or misdirecting message facility.level can cause important messages to be ignored by syslog or overlooked by the administrator.
logger is a command line utility that can send messages to the syslog.
Some implementations permit the filtering and display of syslog messages.
Syslog is now standardized within the Syslog working group of the IETF.
History
Syslog was developed in the 1980s by Eric Allman as part of the Sendmail project, and was initially used solely for Sendmail. It proved so valuable that other applications began using it as well. Syslog has since become the standard logging solution on Unix and Unix-like systems; there have also been a variety of syslog implementations on other operating systems and is commonly found in network devices such as routers.
Syslog functioned as a de facto standard, without any authoritative published specification, and many implementations existed, some of which were incompatible. The Internet Engineering Task Force documented the status quo in RFC 3164. Since then, additions to syslog have been worked on. RFC 3164 was made obsolete by RFC 5424[1]
At different points in time, various companies have attempted patent claims on syslog.[2][3] This has had little effect on the use and standardization of the protocol.
Outlook
Various groups are working on draft standards detailing the use of syslog for more than just network and security event logging, such as its proposed application within the health care environment.
Regulations, such as SOX, PCI DSS, HIPAA, and many others are requiring organizations to implement comprehensive security measures, which often include collecting and analyzing logs from many different sources. Syslog has proven to be an effective format to consolidate logs, as there are many open source and proprietary tools for reporting and analysis. Converters exist from Windows Event Log as well as other log formats to syslog.
An emerging area of managed security services is the collection and analysis of syslog records for organizations. Companies calling themselves Managed Security Service Providers attempt to apply analytics techniques (and sometimes artificial intelligence algorithms) to detect patterns and alert customers of problems.
See also
- Audit trail
- Console server
- Data logging
- Netconf
- Server log
- Simple Network Management Protocol (SNMP)
- Security Event Manager
- Log management and intelligence
- Web log analysis software
- Web counter
- Common Log Format
- Rsyslog
- Syslog-ng
- LogZilla
- Pantheios
- LogParser
References
- ^ R. Gerhards, The Syslog Protocol, RFC 5424
- ^ "LXer: Patent jeopardizes IETF syslog standard".
- ^ "IETF IPR disclosure on HUAWEI's patent claims".
External links
- IETF syslog working group
- SANS Paper The Ins and Outs of System Logging Using Syslog
- NIST SP 800-92 Guide to Computer Security Log Management (PDF)