1.什么是Http 403錯誤
Http協議中對403錯誤定義如下
The server understood the request, but is refusing to fulfill it. Authorization will not help and the request SHOULD NOT be repeated. If the request method was not HEAD and the server wishes to make public why the request has not been fulfilled, it SHOULD describe the reason for the refusal in the entity. If the server does not wish to make this information available to the client, the status code 404 (Not Found) can be used instead.
服務端接收用戶請求，但是拒絕響應。服務器可以返回拒絕響應的原因，如果不希望返回客戶端具體原因，可以使用404（Not Found）來代替。
2.IIS中對Http 403錯誤的詳細分類
403.1 - Execute access forbidden.
服務器禁止執行
403.2 - Read access forbidden.
服務器禁止讀
403.3 - Write access forbidden.
服務器禁止寫
403.4 - SSL required.
必須使用SSL協議訪問服務器
403.5 - SSL 128 required.
必須使用SSL 128協議訪問服務器
403.6 - IP address rejected.
IP地址黑名單
403.7 - Client certificate required.
需要客戶端證書
403.8 - Site access denied.
拒絕訪問服務器
403.9 - Forbidden: Too many clients are trying to connect to the Web server.
連接數太多
403.10 - Forbidden: Web server is configured to deny Execute access.
服務器禁止執行
403.11 - Forbidden: Password has been changed.
服務器訪問密碼已修改
403.12 - Mapper denied access.
403.13 - Client certificate revoked.
客戶端證書不存在
403.14 - Directory listing denied.
不允許訪問目錄
403.15 - Forbidden: Client access licenses have exceeded limits on the Web server.
403.16 - Client certificate is untrusted or invalid.
客戶端證書不被信息
403.17 - Client certificate has expired or is not yet valid.
客戶端證書失效
403.18 - Cannot execute requested URL in the current application pool.
不能執行請求地址
403.19 - Cannot execute CGI applications for the client in this application pool.
不能執行相應的CGI應用接口
403.20 - Forbidden: Passport logon failed.
服務器訪問密碼不對
403.21 - Forbidden: Source access denied.
403.22 - Forbidden: Infinite depth is denied.
403.502 - Forbidden: Too many requests from the same client IP; Dynamic IP Restriction limit reached.
IP訪問限制