HOW TO ENABLE SNMP COMMUNITIES ON ESXI

First, enable ssh on esxi and try to connect by terminal.
after that, execute this command:
#esxcli system snmp set --communities YOUR COMMUNITIE NAME
# esxcli system snmp set --enable true

if you have some issue for test with the command snmpwalk execute this configuration:

# esxcli network firewall ruleset set --ruleset-id snmp --allowed-all true
# esxcli network firewall ruleset set --ruleset-id snmp --enabled true
# /etc/init.d/snmpd restart