Currently, SNMP discoveries are executed through get() and getBulk() calls for low volume exchanges, but it is inefficient when large volumes of data are fetched or when communicating with remote devices. The ASNMP feature allows you to process responses more quickly by packing more requests in one SNMP packet and by handling the code in a faster language. ASNMP is faster than Synchronous SNMP since requests are fired without waiting for a response.

In earlier releases, for any ASNMP request failure, the IP Manager displayed the following error message in the “Description” field of the pending list (AD_PendingData):

SNMP request timed out or had an error

From IP 8.x onwards, by default, ASNMP_Control (Asynchronous SNMP requests) was used. The configurable parameter DoNotUseASNMPPattern in the tpmgr-param.conf file allows you to disable asynchronous requests only for specific devices by SysOID. Add the list of sysOID entries for which you can see one of the following or both the error messages in the “Description” field of the pending list (AD_PendingData) when an ASNMP error occurs during discovery:

"ASNM-E-ASNMP_SEND_RECEIVE_ERROR-ASNMP request failure: Error when sending or
receiving SNMP data for Host '<IP address of the device>' (Maybe bad credentials)."
"ASNM-E-ASNMP_SNMP_ERROR-ASNMP request failure: Error <Error Code>:
<Error Message> when receiving SNMP Packet from '<IP address of the device, port<port number>"

By looking into the error messages, you will know that the errors are related to ASNMP. These are usually caused by the device's inability to process ASNMP requests. Turning ASNMP off for these devices may resolve the issue. Add the sysOID entries separated by “|”, for example:

DoNotUseASNMPPattern .1.3.6.1.4.1.9.5.50|.1.3.6.1.4.9.5.44

The VMware Smart Assurance IP Manager User Guide and the VMware Smart Assurance IP Manager Reference Guide provides information on how to enable ASNMP and on the flag which configures the maximum number of OIDs per packet that can be sent using ASNMP.