NLog Syslog is a custom target for NLog version 4.2.2 allowing you to send logging messages to a UNIX-style Syslog server.

To use NLog Syslog, you simply wire it up as an extension in the NLog.config file and place the NLog.Targets.Syslog.dll in the same location as the NLog.dll & NLog.config files. Then use as you would any NLog target. To use TCP as transport protocol just specify protocol="tcp" in target configuration. Below is a sample NLog.config file:

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

  <extensions>
    <add assembly="NLog.Targets.Syslog" />
  </extensions>

  <targets>
    <target name="syslog" type="Syslog" syslogserver="127.0.0.1" port="514" facility="Local7" sender="MyProgram" layout="[CustomPrefix] ${machinename} ${message}" />
  </targets>

  <rules>
    <logger name="*" minLevel="Trace" appendTo="syslog"/>
  </rules>
</nlog>

The package is also available through NuGet. Simply search for "NLog.Targets.Syslog".

This NLog target provides default values for all configuration options. Optionally, your configuration can override them using attributes on target, as shown in the example configuration above.

• syslogserver: IP or hostname (default: 127.0.0.1)
• port: Port of syslog listener (default: 514)
• protocol: udp or tcp (default: udp)
• ssl: false or true; TCP only (default: false)
• rfc: Rfc compatibility for syslog message Rfc3164 or Rfc5424 (default: Rfc3164)

Messages are sent using the format (framing) called syslog, which is defined in RFC 3164 or RFC 5424. In addition to a timestamp and the log message, RFC 3164 syslog messages include other elements: sending device name (such as the machine's hostname), sending app/component name (called "tag" in the RFC), facility, and severity.

The following syslog elements can be overridden for RFC 3164:

• machinename (Layout): name of sending system or entity (default: machine hostname). For example, ${machinename}
• sender (Layout): name of sending component or application (default: calling method). For example, ${logger}
• facility: facility name (default: Local1)

For example, to make logs from multiple systems use the same device identifier (rather than each system's hostname), one could set machinename to app-cloud. The logs from different systems would all appear to be from the same single entity called app-cloud.

The following additional syslog elements can be overridden for RFC 5424:

• procid (Layout): identifier (numeric or alphanumeric) of sending entity (default: -). For example, ${processid} or ${processname}
• msgid (Layout): message type identifier (numeric or alphanumeric) of sending entity (default: -). For example, ${callsite}
• structureddata (Layout): additional data of sending entity (default: -). For example, [thread@12345 id="${threadid}" name="${threadname}"][mydata2@12345 num="1" code="mycode"]

This target supports the standard NLog layout directive to modify the log message body. The syslog packet elements are not affected.

See more about NLog at: http://nlog-project.org