Advanced Forwarding App

A DNS App for Technitium DNS Server that performs conditional forwarding to configured upstream resolvers.

Overview

Conditional forwarding – route queries by domain and client network
Multiple forwarders – define reusable upstream resolvers
Proxy support – forwarders may use a proxy server definition
Group-based control – forwarding rules are grouped by client network

Integration / extension points

Implements: IDnsApplication, IDnsAuthoritativeRequestHandler, IDnsApplicationPreference
Runs in the authoritative request path when forwarding is enabled.

Configuration

dnsApp.config contains these keys:

Property	Type	Default	Description
`appPreference`	number	`200`	App execution order.
`enableForwarding`	boolean	`true`	Master switch for forwarding.
`proxyServers`	array	`[]`	Proxy server definitions used by forwarders.
`forwarders`	array	`[]`	Forwarder definitions.
`networkGroupMap`	object	required	Maps client networks to group names.
`groups`	array	required	Forwarding groups and their domain/forwarder mappings.

Example

json

{
  "appPreference": 200,
  "enableForwarding": true,
  "proxyServers": [
    {
      "name": "local-proxy",
      "type": "socks5",
      "proxyAddress": "localhost",
      "proxyPort": 1080,
      "proxyUsername": null,
      "proxyPassword": null
    }
  ],
  "forwarders": [
    {
      "name": "quad9-doh",
      "proxy": null,
      "dnssecValidation": true,
      "forwarderProtocol": "Https",
      "forwarderAddresses": ["https://dns.quad9.net/dns-query (9.9.9.9)"]
    }
  ],
  "networkGroupMap": {
    "0.0.0.0/0": "everyone",
    "::/0": "everyone"
  },
  "groups": [
    {
      "name": "everyone",
      "enableForwarding": true,
      "forwardings": [
        {
          "forwarders": ["quad9-doh"],
          "domains": ["*"]
        }
      ]
    }
  ]
}

Runtime behavior

The app selects a client group based on networkGroupMap.
It checks whether forwarding is enabled for the selected group.
It matches the queried domain against the group's forwarding rules.
It returns custom FWD records for matching forwarders.

Risks / operational notes

Overlapping forwarding rules can be hard to reason about.
A bad upstream or proxy definition can break resolution for selected domains.
Keep network group mappings explicit to avoid unintended routing.

Troubleshooting

Confirm the client IP matches a group in networkGroupMap.
Confirm the group has enableForwarding: true.
Confirm the query domain matches one of the group's domains entries.