K4186: Entering escape sequences in health monitor Send and Receive strings Non-Diagnostic Original Publication Date: Jan 9, 2015 Update Date: Feb 7, 2020 Topic When you configure a monitor, the BIG-IP system accepts the following escape sequences within the Send and Receive strings: Escape Sequence Description \a alert (bell) \b backspace \e escape \f formfeed \n newline \r carriage return \t tab \v vertical tab \\ backslash \' single quote You can enter these escape sequences directly into a health monitor's Send and Receive strings as they are represented in the previous table. The BIG-IP system also allows you to enter most hexadecimal or octal characters, using the following special sequences: Escape Sequence Description \xHH Insert the character with the hexadecimal ASCII code of HH. \NNN Insert the character with the octal ASCII code of NNN. To use these special escape sequences, determine the hexadecimal or octal value of the ASCII character that you want to enter and enter the desired sequence, replacing HH or NNN with the appropriate hexadecimal or octal value. For example, to enter a double quote (") , the hexadecimal ASCII code, you can use the double quote escape sequence \x22 hexadecimal or \042 in octal. Note: Prior to BIG-IP 10.2.0, the BIG-IP system does not allow the ASCII character 0 (NUL). Note: Due to a known issue, octal values greater than \077 cannot be used in a Receive string. For more information, refer to K13441: Unable to use octal values greater than \077 in an HTTP monitor Receive string. This issue is fixed in BIG-IP 11.4.0. Supplemental Information K3451: Content length limits for HTTP and HTTPS health monitors K14438: Configuring an HTTP monitor receive string to accept double-byte characters Applies to: Product: BIG-IP, BIG-IP APM, BIG-IP ASM, BIG-IP GTM, BIG-IP Link Controller, BIG-IP LTM 15.1.X, 15.0.X, 14.1.X, 14.0.X, 13.1.X, 13.0.X, 12.1.X, 12.0.X, 11.6.X, 11.5.X, 11.4.X, 11.3.X, 11.2.X, 11.1. X, 11.0.X, 10.2.X, 10.1.X, 10.0.X Product: Legacy Products, BIG-IP WebAccelerator, BIG-IP WOM, BIG-IP PSM, BIG-IP Edge Gateway 15.1.X, 15.0.X, 14.1.X, 14.0.X, 13.1.X, 13.0.X, 12.1.X, 12.0.X, 11.6.X, 11.5.X, 11.4.X, 11.3.X, 11.2.X, 11.1. X, 11.0.X, 10.2.X, 10.1.X, 10.0.X.