Linux::tcp Connections By State - Red Hat NETWORK SATELLITE 5.1.0 Reference Manual

Appendix C. Probes
Field
Timeout*
Warning Minimum Swap Free
Critical Minimum Swap Free
Table C.26. Linux::Swap Usage settings

5.13. Linux::TCP Connections by State

The Linux::TCP Connections by State probe identifies the total number of TCP connections, as
well as the quantity of each in the following states:
• TIME_WAIT — The socket is waiting after close for remote shutdown transmission so it may
handle packets still in the network.
• CLOSE_WAIT — The remote side has been shut down and is now waiting for the socket to
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 addresses or
examining network connections into the monitored system.
The filter parameters for the probe let you narrow the probe's scope. This probe uses the
command to retrieve data. The Local IP address and Local port parameters
netstat -ant
use values in the Local Address column of the output; the Remote IP address and Remote
port parameters use values in the Foreign Address column of the output for reporting.
Requirements — The Red Hat Network Monitoring Daemon (
monitored system to execute this probe.
Field
Local IP address filter pattern list
Local port number filter
Remote IP address filter pattern list
Remote port number filter
Timeout*
Critical Maximum Total Connections
Warning Maximum Total Connections
242
Value
15
) must be running on the
rhnmd
Value
15