Hey, 

After migrating switches from SNMPv2c to SNMPv3, Centreon stopped collecting SNMP data from Dell S4048-ON devices (OS10 Enterprise 10.5.2.2). The same SNMPv3 configuration works perfectly on Cisco Catalyst 9200 switches, but on Dell OS10 devices Centreon consistently returns:
UNKNOWN: Can't construct cache...

SNMP library / plugin used:
/usr/lib/centreon/plugins/centreon_cisco_standard_snmp.pl --plugin=network::cisco::standard::snmp::plugin --mode=interfaces

Test command executed on Centreon host:

/usr/lib/centreon/plugins/centreon_cisco_standard_snmp.pl \ --plugin=network::cisco::standard::snmp::plugin \ --mode=interfaces \ --hostname=10.81.224.12 \ --snmp-version=3 \ --snmp-username='fnsp_snmp' \ --authprotocol='sha' \ --authpassphrase='***' \ --privprotocol='aes' \ --privpassphrase='***'

Output:
UNKNOWN: Can't construct cache...

Manual SNMPv3 test via snmpwalk:

snmpwalk -v3 -l authPriv -u fnsp_snmp \ -a SHA -A '***' \ -x AES -X '***' \ 10.81.224.12 1.3.6.1.2.1.1

Result:
iso.3.6.1.2.1.1 = No more variables left in this MIB View (It is past the end of the MIB tree)

Same result for:

snmpwalk -v3 -l authPriv -u fnsp_snmp \ -a SHA -A '***' \ -x AES -X '***' \ 10.81.224.12 1.3.6.1.2.1.2.2.1.2

Dell S4048 (OS10 Enterprise 10.5.2.2) SNMP configuration:

snmp-server view ALL iso included snmp-server group SNMPv3Group v3 priv read ALL snmp-server user fnsp_snmp SNMPv3Group v3 auth sha *** priv aes *** show snmp group show snmp user

Output:

groupname : SNMPv3Group version : 3 security level : priv readview : ALL User name : fnsp_snmp Group : SNMPv3Group Version : 3 Authentication Protocol : SHA Privacy Protocol : AES

Centreon cache check:
Cache files located in /var/lib/centreon/centplugins/.
For working devices, cache size is typically 20–80 KB.
For the affected host (10.81.224.12), cache size was only 29 bytes:

snmpstandard_10.81.224.12_161_interfaces_*.cache

Steps already tried:

1. Deleted all cache files:

   rm -f /var/lib/centreon/centplugins/*10.81.224.12* rm -f /tmp/centreon/*10.81.224.12*

2. Restarted Centreon poller:

   systemctl restart cbd centengine gorgoned

3. Retested with same command – issue persists.

4. Confirmed Dell SNMPv3 authentication and encryption works via snmpwalk.

5. Reconfigured SNMPv3 user, group, and view on Dell switch.

6. Verified readview ALL and correct security level.

7. Other Dell switches running OS10 show the same behavior.

8. Cisco Catalyst 9200 with identical SNMPv3 settings works correctly.

9. Dell OS10 always responds: No more variables left in this MIB View.

Expected result:
Centreon plugin should retrieve IF-MIB data (interfaces) and construct the SNMP cache as it does on Cisco devices.

Actual result:
Centreon returns UNKNOWN: Can't construct cache... and creates an empty or incomplete cache file (~29 B).

Question for Centreon Support:
Is there any known issue with SNMPv3 handling for Dell OS10 (S4048) devices using the network::cisco::standard::snmp::plugin?
Does this plugin fully support Dell OS10 SNMPv3 responses?
Is there a workaround (for example a different OID, MIB view definition, or forcing IF-MIB mode)?

Summary:

• SNMPv3 (SHA/AES, authPriv) confirmed working.

• Centreon plugin fails to build SNMP cache only for Dell OS10 switches.

• Works fine on Cisco Catalyst 9200 with the same configuration.

• Issue appeared immediately after migrating from SNMPv2c to SNMPv3.