sing-box/docs/configuration/dns/index.md

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icon: material/new-box

!!! quote "Changes in sing-box 1.11.0"

:material-plus: [cache_capacity](#cache_capacity)

DNS

Structure

{
  "dns": {
    "servers": [],
    "rules": [],
    "final": "",
    "strategy": "",
    "disable_cache": false,
    "disable_expire": false,
    "independent_cache": false,
    "cache_capacity": 0,
    "reverse_mapping": false,
    "client_subnet": "",
    "fakeip": {}
  }
}

Fields

Key	Format
server	List of DNS Server
rules	List of DNS Rule
fakeip	FakeIP

final

Default dns server tag.

The first server will be used if empty.

strategy

Default domain strategy for resolving the domain names.

One of prefer_ipv4 prefer_ipv6 ipv4_only ipv6_only.

Take no effect if server.strategy is set.

disable_cache

Disable dns cache.

disable_expire

Disable dns cache expire.

independent_cache

Make each DNS server's cache independent for special purposes. If enabled, will slightly degrade performance.

cache_capacity

!!! question "Since sing-box 1.11.0"

LRU cache capacity.

Value less than 1024 will be ignored.

reverse_mapping

Stores a reverse mapping of IP addresses after responding to a DNS query in order to provide domain names when routing.

Since this process relies on the act of resolving domain names by an application before making a request, it can be problematic in environments such as macOS, where DNS is proxied and cached by the system.

client_subnet

!!! question "Since sing-box 1.9.0"

Append a edns0-subnet OPT extra record with the specified IP prefix to every query by default.

If value is an IP address instead of prefix, /32 or /128 will be appended automatically.

Can be overrides by servers.[].client_subnet or rules.[].client_subnet.