NSX LB service monitoring do not interpret escape characters

Products

• VMware NSX

Issue/Introduction

Symptoms:

• NSX LB Service Monitor configured with a type of TCP and using escape characters (i.e. \r\n) in the send string and the "escape" extension does not translate the escape characters into the correct ascii characters to send the desired codes (i.e. CR LF).
• All the pool members status shows as DOWN.

Environment

VMware NSX for vSphere 6.1.x
VMware NSX for vSphere 6.2.x

Cause

The syntax for using escape characters for TCP checks requires a specific configuration.

Resolution

When the interpretation of escape characters are required in the send string, the following syntax should be used for the Service Monitor configuration:

 

Type: TCP

Send: <leave blank>

Receive: Include the desired receive string, enclosed in double quotes (i.e. "Response: OK")

Extension:

escape

send="send string\\r\\n"

 

Note that in the Extension box:

• the send= command must be on a separate line from the escape command.
• the send string must be enclosed in quotes
• the escape character codes must use double backslashes (\\)
• the escape command should be the first line