Red Hat ENTERPRISE LINUX 5 - DEPLOYMENT Deployment Manual page 628

Chapter 42. Security Overview
xinetd Services
Services controlled by the xinetd super service only run when a there is an active connection.
Examples of services controlled by xinetd include Telnet, IMAP, and POP3.
Because new instances of these services are launched by xinetd each time a new request is
received, connections that occur after an upgrade are handled by the updated software. However,
if there are active connections at the time the xinetd controlled service is upgraded, they are
serviced by the older version of the software.
To kill off older instances of a particular xinetd controlled service, upgrade the package for
the service then halt all processes currently running. To determine if the process is running, use
the ps command and then use the kill or killall command to halt current instances of the
service.
For example, if security errata imap packages are released, upgrade the packages, then type the
following command as root into a shell prompt:
ps -aux | grep imap
This command returns all active IMAP sessions. Individual sessions can then be terminated by
issuing the following command:
kill <PID>
If this fails to terminate the session, use the following command instead:
kill -9 <PID>
In the previous examples, replace <PID> with the process identification number (found in the
second column of the ps command) for an IMAP session.
To kill all active IMAP sessions, issue the following command:
killall imapd
602