When a custom Simple Network Management Protocol (SNMP) community string (for example, Jun10pac31) is used in the Platform menu in the GUI as well as in Connectivity Services Director (CSD), CSD still uses the generic “ public ” as the SNMP community string as opposed to Jun10pac31 . This causes authentication failures.

In this article, you understand what causes this problem and learn how to resolve it.

When the following configuration is used in a device, for example:

test@DEVICE01> show configuration snmp
community Jun10pac31 {
    authorization read-only;
    clients {
        172.10.7.10/32;
    }
}
trap-options {
    source-address 10.61.10.10;
}

A tcpdump taken from the device will show the SNMP community string being used as “ public .”

test@DEVICE01> show log messages | match commu    
Jun 17 03:41:20.164 2018  DEVICE01 snmpd[6443]: SNMPD_AUTH_FAILURE: nsa_log_community: unauthorized SNMP community from 172.10.7.10 to 10.61.10.10 (public)

This is a configuration issue at the device level since the community name should match the trap group name. In the above example, the trap group configuration is missing.

To resolve the issue, correct the configuration at the devices level, as shown below:

test@DEVICE01> show configuration snmp 
community Jun10pac31 {
    authorization read-only;
    clients {
        172.10.7.10/32;
    }
}
trap-options {
    source-address 10.61.10.10;
}
trap-group Jun10pac31 {
    version v2;
    categories {
        authentication;
        chassis;
        link;
        routing;
        startup;
        rmon-alarm;
        configuration;
        services;
    }
    targets {
        172.10.7.10;
    }
}