Symptoms

SNMP status requests consistently fail for a specific Data Domain system. The UI displays the following error in the request history: Could not contact SNMP service on host <DD_hostname>: Unknown host (<DD_hostname>) Debug logs from dpaagent show errors such as: getaddrinfo: <DD_hostname> Hostname and service name not provided or found aapiSNMPOpen(): Failed to open SNMP session for host '<DD_hostname>', errno 0, snmp_error 'Unknown host (<DD_hostname>)'

Cause

The agent host does not have an entry for the Data Domain system in its local hosts file. As a result, it cannot resolve the hostname to an IP address, causing SNMP session initialization to fail.

Resolution

Add the IP address and hostname of the Data Domain system to the hosts file on the agent host. Refer to Microsoft documentation (Ext Link) for details on SNMP hostname resolution. SNMP uses Windows Internet Naming Service (WINS) or the local hosts file to resolve hostnames. If WINS is unavailable, the hosts file must contain correct mappings. Best Practice:Use hostnames instead of IP addresses in SNMP management applications. Ensure that all participating systems have accurate hostname-to-IP mappings in their hosts files. Next Steps:If the issue persists after updating the hosts file, contact the Dell technical support team for further assistance. 

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