mjhjmtu

I created an SNMP initial user several years ago for a project and have forgotten the password. Is there a way to reset net-snmp back to default, no users, and recreate the initial user and subsequent users?
This is on Solaris 10 and Solaris 11.3.

There is a configuration file that is maintained by net-snmp itself. On Debian Linux, it's at /var/lib/snmp/snmpd.conf; I don't know exactly where net-snmp puts it on Solaris. But that file contains user definitions as long lines, starting with the usmUser keyword. The user's password will be stored in encrypted/hashed form, so you cannot read it. But the username will be plainly readable on the line.

You should not edit the file while snmpd is running, as snmpd will then simply overwrite your changes. But when snmpd is stopped, you can edit the file to add a createUser line into it to create a new user - when snmpd is restarted, it will read the file, detect any createUser lines, encrypt the plain-text passwords on those lines, and then replace those createUser lines with corresponding usmUser lines. That way, you could add a new user with a known password and full admin access without knowing the old password, as long as you have write access to that file and can stop snmpd temporarily.

Also, if you remove a user's usmUser line (while snmpd is stopped), then as far as snmpd is concerned, that user no longer exists. So that's one way to delete net-snmp users without knowing the net-snmp admin password.