The latest release of the ISM agent, 220.127.116.11 contains a fix for APAR IV47366 - ismconfig is unable to connect to ITM using secure ports.
18.104.22.168 22.214.171.124-TIV-CAMIS-IF0001 README:
Here are the instructions to configure ismconfig.sh to use SSL:
To set ismconfig to use HTTPS, edit <ITM_HOME>/lx8266/cj/lib/ismco
TepsPort : "3661"
TepsProtocol : "https"
If you have any issues, edit ismconfig.props and set logging to:
TraceParams : "Flow"
Then check /opt/IBM/ITM/logs/ismconfig.lo