ASM OPMS - Telnet monitor not working on new opms (ccagent)

Products

• CA App Synthetic Monitor

Issue/Introduction

Telnet monitor not working on new opms (ccagent). It works fine on new opms (cbot).

Resolution

It says in the Siteminder Documentation that the ports 44441, 44442, and 44443 belong to the Policy Server and are used for accounting, authentication and authorization of SiteMinder Agents. They do not implement the Telnet protocol. The behavior of the Policy Server where it forcefully closes connection on a telnet command is the correct one. Behavior of ccagent where it sends a telnet command and triggers a check error on a forcefully closed connection is also correct.

It is not correct to use Telnet to monitor these endpoints. Instead, Connect monitor should have been chosen.

The only reason why Telnet monitor worked in cbot is, that cbot only opens the TCP connection but does not send any command via the telnet protocol. Thus it is not actually testing telnet, it's just testing the ability to open a TCP/IP connection, just like the Connect monitor does. 

In contrast to that, ccagent not only opens the connection but also sends the 'close' command. If this command fails, it means the monitored endpoint does not implement the telnet protocol.

Additional Information

Customer switched to connect monitor without issues.