236 Appendix C. ProbesC.5.12. Linux::Swap UsageThe Linux::Swap Usage probe monitors the swap partitions running on a system and re-ports the following metric:• Swap Free — The percent of swap memory currently free.Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be runningon the monitored system to execute this probe.Field ValueTimeout* 15Warning Minimum Swap FreeCritical Minimum Swap FreeTable C-26. Linux::Swap Usage settingsC.5.13. Linux::TCP Connections by StateThe Linux::TCP Connections by State probe identifies the total number of TCP connec-tions, as well as the quantity of each in the following states:• TIME_WAIT — The socket is waiting after close for remote shutdown transmission soit may handle packets still in the network.• CLOSE_WAIT — The remote side has been shut down and is now waiting for the socketto close.• FIN_WAIT — The socket is closed, and the connection is now shutting down.• ESTABLISHED — The socket has a connection established.• SYN_RCVD — The connection request has been received from the network.This probe can be helpful in finding and isolating network traffic to specific IP addressesor examining network connections into the monitored system.The filter parameters for the probe let you narrow the probe’s scope. This probe uses thenetstat -ant command to retrieve data. The Local IP address and Local port param-eters use values in the Local Address column of the output; the Remote IP address andRemote port parameters use values in the Foreign Address column of the output for re-porting.Requirements — The Red Hat Network Monitoring Daemon (rhnmd) must be runningon the monitored system to execute this probe.
