Watch a network using syslog
One of the traditional tools for the generation of logs is called syslog. Syslog is a protocol designed to send log entries generated by a device or process called a facility across an IP network to a message collector, called a syslog server.
Syslog messages begin with two numerical codes. The first code identifies the facility that generated the message, some examples of which are as follows:
- 0 Kernel messages
- 1 User-level messages
- 3 System daemons
- 4 Security/authorization messages
- 5 Messages generated internally by syslog
- 6 Line printer subsystem
- 7 Network news subsystem
- 8 UUCP subsystem
- 9 Clock daemon
- 10 Security/authorization messages
- 11 FTP daemon
- 12 NTP subsystem
- 0 Emergency: system is unusable
- 1 Alert: action must be taken immediately
- 2 Critical: critical conditions
- 3 Error: error conditions
- 4 Warning: warning conditions
- 5 Notice: normal but significant condition
- 6 Informational: informational messages
- 7 Debug: debug-level messages
Subsequent parts of the Syslog message format include a structured data section, which contains information in a format easily parsable by other software entities, and a free-form message section intended to carry more specific information about the event.
Answer: True. Syslog has become ubiquitous on the UNIX and Linux platforms and is common on other operating systems as well, including Windows.
Answer: True. Syslog was developed in the 1980s for use with sendmail, the de facto standard in Simple Mail Transfer Protocol (SMTP) mail servers. It enables sendmail to record its activities in a text-based log file. Since then, it has come to be used for the same purpose with a variety of applications and processes.