“如果请求中包含了Range请求头,并且Range中指定的任何数据范围都与当前资源的可用范围不重合,同时请求中又没有定义If-Range请求头,那么服务器就应当返回416状态码。“ — wikipedia
“A server SHOULD return a response with this status code if a request included a Range request-header field, and none of the range-specifier values in this field overlap the current extent of the selected resource, and the request did not include an If-Range request-header field. (For byte-ranges, this means that the first- byte-pos of all of the byte-range-spec values were greater than the current length of the selected resource.)
When this status code is returned for a byte-range request, the response SHOULD include a Content-Range entity-header field specifying the current length of the selected resource. This response MUST NOT use the multipart/byteranges content- type.“ — ietf