SNMPD is a simple transport model for sending data (and possibly commands) between different system. The [[[Cacti]] system uses it to get information from the various devices, including the "Sensorhawk".
yum installl net-snmp
This will also get lm-sensors if it wasn't already installed. You would probably want to configure it up, which is in /etc/snmp/. On einstein (and others) there is a perl script there in an attempt to create something that can pull more info from snmp. This is work in progress.
You also want some of the tools, including snmpwalk with:
yum install net-snmp-utils
You can get info from snmp with the command "snmpget", but in general "snmpwalk" is easier. It allows you to walk through the tree of available snmp information and thus get a full view of the system.
To test the public space:
snmpwalk -v 1 -c public localhost .1
To test the NPG information:
snmpwalk -v 1 -c NPG localhost .1
To see if you can access from a different system, log into that system:
snmpwalk -v 1 -c NPG einstein.farm.physics.unh.edu .1
Access control and config
See /etc/snmp/snmpd.conf. This is where you allow/restrict access and can control what is presented. If only you could figure out the file.
Log Level control
Logging is controlled on the command line, see the logging options in snmpcmd man page The actual file to change is /etc/sysconfig/snmpd.options or /etc/snmpd/snmpd.options where the line
OPTIONS="-LS 0-4 d -Lf /dev/null -p /var/run/snmpd.pid -a"
OPTIONS="-LF0-3 /var/log/snmpd.log -p /var/run/snmpd.pid -a"
has the necessary magic. See /etc/init.d/snmpd for the defailt.