Nagios problems after SNMP community change

Hello everyone!

I’m new in nagios and snmp monitoring. So I’he got some problems with Nagios. I’ve isnattled it and everything was all right with default settings until I’ve changed SNMP community string on my network devices from “public” to “custom_community”. After that Nagios tell that "SNMP problem - No data received from host ". As I think, I should change SNMP community string somewhere, but I don’t know exactly where. I’ve changed my snmpd.conf to

syslocation my_city
syscontact admin@my_domain (configure /etc/snmp/snmp.local.conf)
rwcommunity custom_community <my_nagios_server_ip>

but that is no use.
Please help me to configure Nagios correct.

check in your service.cfg and command.cfg… somewhere you’ll find th eold community…
in the objects directory try
grep public *