putty cannot connect to 3PAR after upgrading to 3.3.1 MU3

Recently I upgraded a new 3PAR from 3.2.2 MU6 to 3.3.1 MU3. Even during the upgrade I could use me putty to run commands in 3PAR console. After the upgrade process activated 3.3.1 MU3, no putty session could be established any more. When trying to connect, the error appears:

Network error: Software caused connection abort

It turned out this is because no older TLS version than 1.2 can be used to connect any more. My version of putty was not aware of this. After installing the latest version (0.70) I could connect without errors. I am quite sure, this is new to MU3. Probably because of new security features respectively default settings (new command: controlsecurity for FIPS).

Notes

• Find Command Reference Guide incl. MU3 here.
• Find Release nodes, incl. MU3 here.