you can create a parameter similar to the following:
<parameter> <parameterName value="@machine" /> <dbType value="String" /> <size value="255" /> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%X{machine}" /> </layout> </parameter> Then add this line before writing to the log: MDC.Set("machine", Environment.MachineName);MDC.Set("machine", Environment.MachineName);