In communication between the network element (NE) and network management station (workstation), an SNMP error code returned by the NE in response to SNMP requests can provide error information, such as excessive packet length and nonexistent index. The error code defined by SNMP is called the standard error code.
The SNMP protocol stack provides 21 types of standard error codes:
Five are specialized for SNMPv1.
Sixteen are shared by SNMPv2 and SNMPv3.
With an increasing number of system features and scenarios, the current SNMP standard error code types are inadequate. Consequently, the workstation cannot identify the scenario where the fault occurs when the NE processes packets. As a solution, the extended error code was introduced.
When a fault occurs during packet processing, the NE returns an error code corresponding to the fault scenario. If the fault scenario is beyond the range of the SNMP standard error code, a generic error or a user-defined error code is returned.
The error code that is defined by users is called the extended error code.
The extended error code applies to more scenarios. Only Huawei workstations can correctly parse the fault scenario of the current NE based on the agreement with NEs.
Extended error code can be enabled using either command lines or operations on the workstation. After extended error code is enabled, SNMP converts the internal error codes returned from features into different extended error codes and then sends them to the workstation based on certain rules. If the internal error codes returned from features are standard error codes, SNMP sends them directly to the workstation.
If extended error code is disabled, standard error codes and internal error codes defined by modules are sent directly to the workstation.
The system generates and manages extended error codes based on those registered on the modules and the module number. The workstation parses extended error codes according to its agreement with NEs and then displays the obtained information.