Our "WhiteBoard Wednesday" video series will highlight really cool and exciting features of the BIG-IP.  In this video, I take a few minutes to walk through the workflow of an HTTP monitor  and discuss the differences between the content and application health check monitors. Enjoy!


Clarifications on the Receive Disable String

A few individuals have asked about the timing regarding the receive disable string (and the reverse option) in the monitors. To clarify, the action on receive disable is immediate unless neither the receive nor the receive disable strings match, then it falls back to the timeout process. This table should help:


Matches Receive Str Matches Receive Disable Str Status Icon Timing
YES YES Up (Enabled) Green Circle Immediate
YES NO Up (Enabled) Green Circle Immediate
NO YES Up (Disabled) Black Circle Immediate
NO NO Down (Disabled) Black Diamond Timeout Process

Clarification on the Reverse Option

Also in the monitor, but not directly discussed in the video, is the option to mark the pool member down if the receive string is matched by selecting the reverse option in the monitor configuration. Whereas the receive disable setting is more ideal for controlling graceful entry into maintenance windows (by allowing active/persistent connections,) the reverse option immediately marks the pool members hard down.