DNS Servers

DNS servers are referenced by DNS rules inside each routing mode. They are also used as internal DNS servers when vx-core resolves domain names while dialing outbounds.

How DNS queries are handled

There are two types of queries:

Hijacked DNS — Queries from other apps (TUN mode or when system DNS points at vx-core). The are matched against Dns Rules.

Internal DNS — When vx-core itself needs to resolve a domain (for example a node with a domain address). The mode's ordered internal DNS servers list is tried left to right until one succeeds.

For both, DNS records are checked first. If a record matches the query, vx-core returns that answer immediately and does not forward to a DNS server.

DNS server types

When you add a DNS Server, choose a type from the dropdown. Each type is a single resolver implementation.

Type	What it does
Fake	Return fake IPs from configured CIDR pools (typically `198.18.0.0/15`).
UDP/TCP	Classic DNS over UDP/TCP to one or more `host:port` addresses. Multiple addresses can be comma-separated; each query is sent to all of them at once and the first reply is used.
HTTPS	DNS over HTTPS (DoH) to a resolver URL (for example `https://1.1.1.1/dns-query`).
TLS	DNS over TLS (DoT) to one or more `host:port` addresses.
QUIC	DNS over QUIC.
Go	Uses the Go runtime / system DNS resolver (OS resolver behavior). Its traffic does not go through routing, it is typically used in servers and non-TUN modes.
Empty	Always returns an empty DNS answer (no records).

Common fields (most types)

Field	Purpose
Name	Unique tag used in DNS rules and internal DNS server lists. Cannot duplicate another server or composite name. The name `hijack` is reserved.
Client IP	Optional ECS (EDNS Client Subnet) source address sent with queries so upstream resolvers return answers for your location.
Cache duration	How long to cache responses in seconds. If empty or `0`, cache until the record TTL expires.
Result IP set	After resolution, drop A/AAAA answers whose IPs are not in the selected IP sets. This can be used to prevent DNS pollution

Fake DNS fields

Field	Purpose
Pool	Comma-separated CIDRs for fake IP allocation (for example `198.18.0.0/15`).
LRU size	How many fake DNS mappings to keep per pool (default in the form is 6666).

Composite DNS servers

Besides single resolvers, you can create groups that combine other DNS servers by name:

Concurrent DNS Server

Runs all member servers in parallel and returns the first definitive answer (NOERROR with at least one record). Empty NOERROR answers are kept only as fallbacks if no server returns a definitive answer.

Use this when you want the fastest resolver among several upstreams (for example 8.8.8.8 and 1.1.1.1 at the same time).

Serial DNS Server

Queries member servers in order, but starts the next server after an interval (seconds) if no definitive answer has arrived yet. Earlier queries keep running in the background, so a slow-but-correct upstream can still win.

Use this when you prefer a primary resolver with timed fallbacks (for example try domestic DNS first, then foreign DNS resolvers).

Both composite types require at least one member DNS server. Member order matters for serial groups (reorder in the form).

DNS records

Each record has:

Field	Purpose
Domain	Hostname to match (required).
IP addresses	Comma-separated IPv4 and/or IPv6 addresses. Creates A and AAAA answers.
Proxied domain	Optional CNAME target — the domain resolves to this name instead of direct IPs.

Applied to all DNS queries

DNS records are evaluated for every DNS query — hijacked app queries and vx-core internal lookups alike.

vx-core checks static records before DNS rules and before upstream resolvers. If the query name and type match a record, that answer is returned immediately.

This is useful for:

Blocking or redirecting specific domains without changing routing rules
Pinning a domain to a fixed IP for testing
Local development hostnames

Routing modes — DNS rules and internal DNS servers per mode
TUN Mode — DNS hijack on the TUN interface
DNS Policy — global DNS options in Settings