3.3.5.17 Receiving an SMB2 ECHO Request
When the server receives a request with an SMB2 header with a Command value equal to SMB2 ECHO, message handling proceeds as follows:
If Connection.SessionTable is empty, the server SHOULD<399> disconnect the connection.
The server MUST verify the session, as specified in section 3.3.5.2.9, if any of the following conditions is TRUE:
SMB2_FLAGS_SIGNED bit is set in the Flags field of the SMB2 header of the request.
The request is not encrypted, and the SessionId field of the SMB2 header of the request is not zero.
The server MUST construct an SMB2 ECHO Response following the syntax specified in section 2.2.29 and MUST send it to the client.
The status code returned by this operation MUST be one of those defined in [MS-ERREF]. Common status codes returned by this operation include:
STATUS_SUCCESS
STATUS_INVALID_PARAMETER