After upgrading from a non-k9 to k9 image, SSH may fail. :
: Identifies the feature license tier. The "IP Services" designation unlocks full Layer 3 routing capabilities, including advanced enterprise protocols. The "k9" string indicates the inclusion of strong cryptographic features (such as SSH, HTTPS, and SNMPv3) subject to export control laws. C3560-ipservicesk9-mz.150-2.se11.bin