Using these instructions I set up SNMP v3 on my Cisco 2950-T switch. I was not able to use DES encryption because the switch does not have a crypto image. This output has the clues I need to track down what image I’m using. Using an snmpv3 user could cause a bootup delay, according to the output. I believe a router I own has a crypto. image, so to enable DES encryption of SNMP. packets I would say this instead: “A bejtlichpass””]
Source: https://taosecurity.blogspot.com/2006/08/snmp-v3-on-cisco-switch.html