Web OS 10.0 Application GuideChapter 10: Health Checking n 223212777-A, February 2002Link Health ChecksLink health check is performed at the Layer 1 (physical) level. The server is considered to beup when the link (connection) is present and the server is considered to be down when the linkis absent. These checks are used on servers that do not respond to any other health checks.Intrusion Detection Servers (IDSs) fall into this category. Many IDSs have two physicalinterfaces. One is used to detect intrusions, and the other is used to generate logging. The firstinterface detects intrusions but it does not have TCP/IP stack. So it is not possible to performany health check other than Layer 1 health checking on the IDS. As long as the physical linkbetween the switch and the IDS is up, it indicates the IDS is alive.To perform this health check, a link option has been added to the real server group health com-mand. The real server number is used to determine which port the server is connected to. Forexample, real server 1 is assumed to be connected to port 1. The valid IDS real server numbersare from 1 to 9 when health check is in use.Configuring the Switch for Link Health ChecksConfigure the switch to verify if the IDS server is alive by performing the following tasks:1. Select the health check menu for real server group 1.2. Set the health check type to link for real server group 1.3. Apply and save your configuration.>> # /cfg/slb/group 1>> # Real server group 1# healthCurrent health check type: tcpEnter health check type: link>> # Real server group 1# apply>> # Real server group 1# save
