Data Protection Advisor: Data Domain systems are missing in the Data Domain Capacity Utilization report

All SNMP-based data collection requests for Data Domain systems missing in the Data Domain Capacity Utilization report failed with the following error message:

Either host is down or invalid credentials have been provided

All SSH-based data collection requests complete successfully.  Within the debug low dpaagent.log, the SNMP requests a timeout attempting to collect information and then return the above error message:

DBG1    21920.22184    20200206:143435        agent.manager - agentManagerRunRequest(): Running request datadomain:status for target <DD_hostname>
 >>
DBG2    21920.22184    20200206:143435             com.snmp - _aapiSNMPGetPDU(): attempting to get OID 1.3.6.1.4.1.19746.1.13.1.1.0
 >>
DBG2    21920.22184    20200206:165435        com.base.i18n - convertToUTF8Data(): convdata->conv is NULL
DBG1    21920.22184    20200206:165435             com.snmp - _aapiSNMPGetPDU(): request timed out
 >>
DBG2    21920.22184    20200206:165435             com.snmp - _aapiSNMPGetPDU(): attempting to get OID 1.3.6.1.2.1.1.1.0
 >>
DBG2    21920.22184    20200206:191435        com.base.i18n - convertToUTF8Data(): convdata->conv is NULL
DBG1    21920.22184    20200206:191435             com.snmp - _aapiSNMPGetPDU(): request timed out
DBG2    21920.22184    20200206:191435        com.base.i18n - convertToUTF8Data(): convdata->conv is NULL
ERR     21920.22184    20200206:191435         agent.mod.dd - status_snmp(): Either host[<DD_hostname>] is down or invalid credentials has been provided
 >>
DBG1    21920.22184    20200206:191435       agent.reporter - agentReportSend(): successfully sent report to server https://127.0.0.1:9002/dpa-api/agent/93616105-8123-4501-ab05-16c0cdfb595c/report
DBG1    21920.22184    20200206:191435       agent.reqqueue - aapiReturnAgentRequest(): Request datadomain:status for target <DD_hostname>: will next run at 1581038975

The Data Domain system is configured with multiple NICs and IPs.  When running nslookup from the DPA Agent against the Data Domain short name, it resolves to multiple IP addresses where only one of the IPs (a.b.c.130) is the management interface:

nslookup <DD_short_name>
Server:  <DNS_server_hostname>
Address:  <DNS_server_IP_address>

Name:    <DD_FQDN>
Addresses:  a.b.c.135
          a.b.c.133
          a.b.c.130
          a.b.c.132
          a.b.c.131
          a.b.c.136
          a.b.c.138
          a.b.c.134
          a.b.c.137

Running snmpwalk against the Data Domain hostname (is below) from the DPA agent fails.

snmpwalk.exe -r:<DD_hostaname> -c:public -v:2c -p:161

Running snmpwalk against the IP address of the management interface (a.b.c.130) completes successfully and returns data from the Data Domain.

The Data Domain system was configured to use multiple interfaces, but only the management interface accepts incoming SNMP requests.

The following steps can be taken to resolve the issue:

1. Log in to the DPA Agent system
2. Browse to the hosts file (location depends on O/S)
3. Open host file with a text editor
4. Add or update entry for Data Domain hostname so the management interface IP is now listed
5. Restart the DPA Agent services

Contact Dell Technical Support for further details or information.