Configuring a Probe for Server Load Balancing (S-Series)

Server load balancing provides the ability to assign two probes to monitor a real server. ICMP probe monitoring of a real server occurs by default, using the predefined ICMP probe $slb_default, assigned to probe one. See Preset Default ICMP Probes for preset default ICMP probe details.

Probes are assigned to a real server configuration using the faildetect probe command in real server configuration mode. When assigning a probe to a real server, specify probe one or two, and the name of the probe. Any preexisting probe is overwritten when assigning a probe.

Default ICMP probes can not be assigned by specifying the name of the probe. When probe one has not been administratively configured, the default ICMP probe for that server context is auto-configured for probe one.

Layer 7 real server applications can be verified by configuring a TCP or UDP probe with ACV.

This example shows how to:

• Create a TCP probe named TCP-HTTP
• Set the fail detection interval to 5 seconds
• Set the pass detection interval to 5 seconds
• Configure the ACV request and reply strings
• Place the probe inservice
• Display a detailed level of configuration information for the probe
• Assign the probe to probe one of the 10.1.2.3 port 80 real server in the server farm myproductHTTP:
• Enable the real server configuration

  System(su)->configure
  System(su-config)->probe TCP-HTTP tcp
  System(su-config-probe)->faildetect interval 5
  System(su-config-probe)->passdetect interval 5
  System(su-config-probe)->acv request “GET / HTTP/1.1\\r\\nHost: 2.0.0.5\\r\\n\\r\\n”
  System(su-config-probe)->acv reply “HTTP/1.1 200 OK\\r\\n”
  System(su-config-probe)->inservice
  System(su-config-probe)->show probe TCP-HTTP detail
  Probe:                        TCP-HTTP  Type:                           tcp-acv
  Administrative state:        inservice  Session count:                        1
  Fail-detect count:                   3  Pass-detect count:                    3
  Fail-detect interval:                5  Pass-detect interval:                 5
  3-way TCP handshake wait time:       5  Server response wait time:           10
  Application Content Verification:
   Request-string: GET / HTTP/1.1\\r\\nHost: 2.0.0.5\\r\\n\\r\\n
   Reply-string:   HTTP/1.1 200 OK\\r\\n
   Close-string:
   Search-Depth:   255
  System(su-config-probe)->exit
  System(su-config)->ip slb serverfarm myproductHTTP
  System(su-config-slb-sfarm)->real 10.1.2.3 port 80
  System(su-config-slb-real)->faildetect probe one TCP-HTTP
  System(su-config-slb-real)->inservice
  System(su-config-slb-real)->