neo@debian:~$ sudo /etc/init.d/snmpd stop
Stopping network management services: snmpd snmptrapd.

neo@debian:~$ sudo net-snmp-config --create-snmpv3-user -ro -a "netadminpassword" netadmin
adding the following line to /var/lib/snmp/snmpd.conf:
   createUser netadmin MD5 "netadminpassword" DES
adding the following line to /usr/share/snmp/snmpd.conf:
   rouser netadmin

neo@debian:~$ sudo /etc/init.d/snmpd start
Starting network management services: snmpd.
		

test

		
neo@debian:~$ snmpget -v 3 -u netadmin -l authNoPriv -a MD5 -A <passwd> 127.0.0.1 sysUpTime.0
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (6342) 0:01:03.42
		
		

With a different password this fails:

neo@debian:~$ snmpget -v 3 -u netadmin -l authNoPriv -a MD5 -A nopasswd 127.0.0.1 sysUpTime.0
snmpget: Authentication failure (incorrect password, community or key) (Sub-id not found: (top) -> sysUpTime)
		

Note that this can be stuck in a snmp.conf file in ~/.snmp:

		
neo@debian:~$ mkdir ~/.snmp
neo@debian:~$ vim ~/.snmp/snmp.conf
defSecurityName netadmin
defContext ""
defAuthType MD5
defSecurityLevel authNoPriv
defAuthPassphrase <netadminpassword>
defVersion 3
		
		

test

neo@debian:~$ snmpget 127.0.0.1 sysUpTime.0
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (39471) 0:06:34.71