Updated Troubleshooting (markdown)

Troubleshooting.md

@@ -6,6 +6,8 @@
 4. 如果本地端没有收到请求，检查浏览器代理设置，检查本地防火墙。如果日志中只有 IP 没有域名，确保你本地做了防 DNS 污染，否则就配置浏览器远程解析域名。
 5. 如果服务端没有收到请求，检查服务器防火墙，在本地用 tcping 等端口扫描工具检查服务器端口有没有打开。
 6. 如果服务端收到了请求，但浏览器没有载入内容，检查服务端的 DNS `/etc/resolv.conf`，改为 `8.8.8.8` 再重启服务端。
+7. 如果服务端速度慢，可能无良 ISP 做了 QoS，更换端口到 `80` `25` `443` `995` `3389` 等常用端口再测试。
+8. 如果服务端启动时提示权限问题，可能是系统限制了 <1024 端口权限，用 iptables 做转发即可 `iptables -t nat -A PREROUTING -p tcp --dport 995 -j REDIRECT --to-ports 8387`
 
 When you have problems, follow the steps below to diagnose:
 
@@ -15,3 +17,5 @@ When you have problems, follow the steps below to diagnose:
 4. If the client did not receive any requests, check proxy settings and local firewall.
 5. If the server did not receive any requests, check server firewall and use `tcping` to check server port.
 6. If the server received requests but your browser got no responses, check the DNS on your server. Change it into `8.8.8.8`, restart your server and test again.
+7. If the server is slow, change your server port into common port like `80` `25` `443` `995` `3389`.
+8. If you see `Permission Denied` when server starts, use `iptables` to redirect ports<1024 to ports>1024 `iptables -t nat -A PREROUTING -p tcp --dport 995 -j REDIRECT --to-ports 8387`