When you have an SNMP polling service running like Cacti, you can poll your Ubuntu machine's easily in a few steps.
1. install snmpd (snmp deamon)sudo apt-get install snmpd
2. now edit the settings filesudo vim /etc/snmp/snmpd.conf
3. comment out when the SNMP polling server is not running on the local host:#agentAddress udp:127.0.0.1:161
4. add listen on all interfaces for both IPv4 and IPv6 UDP 161agentAddress udp:161,udp6:[::1]:161
5 option 1. scroll further down and add above "rocommunity secret" (your polling community string "secret" and your polling server ip address i.e.; Cacti): rocommunity secret 192.168.1.100
5 option 2. or with FQDNrocommunity ForgeMe123 cacti.example.com
6. Save the config and restart services:sudo service snmpd restart