NEDNSProxyProvider:DNS based on HTTP supported in iOS11

## [NEDNSProxyProvider](https://developer.apple.com/documentation/networkextension/nednsproxyprovider?language=objc)

- [NEDNSProxyProviderProtocol](https://developer.apple.com/documentation/networkextension/nednsproxyproviderprotocol?language=objc)
- [NEDNSProxyManager](https://developer.apple.com/documentation/networkextension/nednsproxymanager?language=objc)


Receives the system’s DNS query messages Handles them as it wishes

Can send to recursive resolver of its choice Can send using protocol of its choice

- DNS over TLS
- DNS over HTTP

And this API is only useful to VPN APP



[**DNS Proxy provider: also for non-managed devices?**]( https://forums.developer.apple.com/thread/79636)

Reference:

- Video Reference: [707_advances_in_networking_part_1](https://developer.apple.com/videos/play/wwdc2017/707/) 18':20''
- Video Reference:[Advances in Networking, Part 2](https://developer.apple.com/videos/play/wwdc2017/709/) 42'15''
- PDF Reference: [707_advances_in_networking_part_1](https://devstreaming-cdn.apple.com/videos/wwdc/2017/707h2gkb95cx1l/707/707_advances_in_networking_part_1.pdf
)

## [NEAppProxyProvider](https://developer.apple.com/documentation/networkextension/neappproxyprovider?language=objc)

- [《iOS 9 Network Extension VPN API 编程指南-》]( http://www.hideme.io/blog/zh-CN/ios-9-vpn-api-network-extension-udp/ )
- Video Reference: [707_advances_in_networking_part_1](https://developer.apple.com/videos/play/wwdc2015/717/) 30'17''

- [iOS 11 - New MDM payloads](https://emm.how/t/ios-11-new-mdm-payloads/431)
- [Apple Developer Forums / Core OS / Networking >VPN DNS](https://forums.developer.apple.com/thread/83731)
- [**Re: DNS settings not work for tunnel**]( https://forums.developer.apple.com/message/122209#122209)

Start by reviewing the linked Apple NEDNSProxyProvider and NEAppProxyProvider documentation, WWDC references, and forum discussions. Then inspect the repository's existing iOS 11 adaptation materials to determine where this topic belongs; done should mean a clearly scoped, validated explanation of the supported DNS proxy behavior and limitations.

Written by the indexing model from the issue text.