Enable SNMP on ESX server.

First of all you will need a vmware CLI.
One installed lauche the following commands:

Set comunity:
vicfg-snmp.pl --server --username root --password -c

Set Trap destination:
vicfg-snmp.pl --server --username root --password -t @/

Set snmp get port:
vicfg-snmp.pl --server --username root --password -p

 Enable deamon:
 vicfg-snmp.pl --server --username root --password --enable

That's it
Ciao