HOWTO via the command line:
Edit /etc/hostconfig; find SNMPSERVER=-NO- and change to YES. This
will enable snmp at system startup Next edit /etc/snmpd.conf; simplified
example below. Change public to something secure. This is a read, query,
only community.
###########################################################################
#
# snmpd.conf
#
# - created by the snmpconf configuration program
#
###########################################################################
# SECTION: Access Control Setup
#
# This section defines who is allowed to talk to your running
# snmp agent.
# rocommunity: a SNMPv1/SNMPv2c read-only access community name
# arguments: community [default|hostname|network/bits] [oid]
rocommunity public
Next you want start/restart the snmp daemon:
sudo /System/Library/StartupItems/SNMP/SNMP restart
Any questions let me know.