Update ReadMe.md

ReadMe.md

@@ -595,6 +595,7 @@ https://github.com/pymumu/smartdns/releases
     * 高速缓存机制，使访问更快速。
     * 异步日志，审计机制，在记录信息的同时不影响DNS查询性能。
     * 域名组（group）机制，特定域名使用特定上游服务器组查询，避免隐私泄漏。
+    * 第二DNS支持自定义更多行为。
 
 1. 如何配置上游服务器最佳。  
     smartdns有测速机制，在配置上游服务器时，建议配置多个上游DNS服务器，包含多个不同区域的服务器，但总数建议在10个左右。推荐配置  
@@ -648,7 +649,12 @@ https://github.com/pymumu/smartdns/releases
     nameserver /.office/office
     ```
 
-    通过上述配置即可实现DNS解析分流
+    通过上述配置即可实现DNS解析分流，如果需要实现按请求端端口分流，可以配置第二DNS服务器，bind配置增加--group参数指定分流名称。
+
+    ```sh
+    bind :7053 -group office
+    bind :8053 -group home
+    ```
 
 1. IPV4, IPV6双栈IP优选功能如何使用  
     目前IPV6已经开始普及，但IPV6网络在速度上，某些情况下还不如IPV4，为在双栈网络下获得较好的体验，smartdns提供来双栈IP优选机制，同一个域名，若IPV4的速度远快与IPV6，那么smartdns就会阻止IPV6的解析，让PC使用IPV4访问，具体配置文件通过`dualstack-ip-selection yes`启用此功能，通过`dualstack-ip-selection-threshold [time]`来修改阈值。如果要完全禁止IPV6 AAAA记录解析，可设置`force-AAAA-SOA yes`。
@@ -667,6 +673,14 @@ https://github.com/pymumu/smartdns/releases
     通过`prefetch-domain yes`来启用域名预先获取功能，提高查询命中率。  
     配合上述ttl超时时间，smartdns将在域名ttl即将超时使，再次发送查询请求，并缓存查询结果供后续使用。频繁访问的域名将会持续缓存。此功能将在空闲时消耗更多的CPU。
 
+1. 第二DNS如何自定义更多行为  
+    第二DNS可以作为其他DNS服务器的上游，提供更多的查询行为，通过bind配置支持可以绑定多个端口，不同端口可设置不同的标志，实现不同的功能，如
+
+    ```sh
+    # 绑定 6053端口，6053端口的请求将采用配置office组的上游查询，且不对结果进行测速，忽略address的配置地址。
+    bind [::]:6053 -no-speed-check -group office -no-rule-addr
+    ```
+
 ## Donate
 
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ReadMe_en.md

@@ -591,6 +591,7 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
     * Cache mechanism to make access faster.
     * Asynchronous log, audit log mechanism, does not affect DNS query performance while recording information.
     * Domain group mechanism, specific domain names use specific upstream server group queries to avoid privacy leakage.
+    * The second DNS supports customizing more behavior.
 
 1. What is the best practices for upstream server configuration?  
     Smartdns has a speed measurement mechanism. When configuring an upstream server, it is recommended to configure multiple upstream DNS servers, including servers in different regions, but the total number is recommended to be around 10. Recommended configuration
@@ -645,6 +646,13 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
     Nameserver /.office/office
     ```
 
+    You can use the above configuration to implement DNS resolution and offload. If you need to implement traffic distribution on the requesting port, you can configure the second DNS server. The bind configuration is added. The group parameter specifies the traffic distribution name.
+
+    ```sh
+    Bind :7053 -group office
+    Bind :8053 -group home
+    ```
+
 1. How to use the IPV4, IPV6 dual stack IP optimization feature  
     At present, IPV6 network is not as fast as IPV4 in some cases. In order to get a better experience in the dual-stack network, SmartDNS provides a dual-stack IP optimization mechanism, the same domain name, and the speed of IPV4. Far faster than IPV6, then SmartDNS will block the resolution of IPV6, let the PC use IPV4, the feature is enabled by `dualstack-ip-selection yes`, `dualstack-ip-selection-threshold [time]` is for threshold. if you want to disable IPV6 AAAA record complete, please try `force-AAAA-SOA yes`.
 
@@ -662,6 +670,14 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
     Enable pre-fetching of domain names with `prefetch-domain yes` to improve query hit rate.
     by default, Smartdns will send domain query request again before cache expire, and cache the result for the next query. Frequently accessed domain names will continue to be cached. This feature will consume more CPU when idle.
 
+1. How does the second DNS customize more behavior?
+    The second DNS can be used as the upstream of other DNS servers to provide more query behaviors. Bind configuration support can bind multiple ports. Different ports can be set with different flags to implement different functions, such as
+
+    ```sh
+    # Binding 6053 port, request for port 6053 will be configured with the upstream query of the office group, and the result will not be measured. The address configuration address is ignored.
+    bind [::]:6053 -no-speed-check -group office -no-rule-addr
+    ```
+
 ## [Donate](#Donate)  
 
 If you feel that this project is helpful to you, please donate to us so that the project can continue to develop and be more perfect.