sing-box/docs/configuration/shared/listen.md

Structure

{
  "listen": "::",
  "listen_port": 5353,
  "tcp_fast_open": false,
  "udp_fragment": false,
  "sniff": false,
  "sniff_override_destination": false,
  "sniff_timeout": "300ms",
  "domain_strategy": "prefer_ipv6",
  "udp_timeout": 300,
  "proxy_protocol": false,
  "proxy_protocol_accept_no_header": false,
  "detour": "another-in"
}

Fields

Field	Available Context
listen	Needs to listen on TCP or UDP.
listen_port	Needs to listen on TCP or UDP.
tcp_fast_open	Needs to listen on TCP.
udp_timeout	Needs to assemble UDP connections, currently Tun and Shadowsocks.
proxy_protocol	Needs to listen on TCP.
proxy_protocol_accept_no_header	When proxy_protocol enabled

listen

==Required==

Listen address.

listen_port

Listen port.

tcp_fast_open

Enable TCP Fast Open.

udp_fragment

Enable UDP fragmentation.

sniff

Enable sniffing.

See Protocol Sniff for details.

sniff_override_destination

Override the connection destination address with the sniffed domain.

If the domain name is invalid (like tor), this will not work.

sniff_timeout

Timeout for sniffing.

300ms is used by default.

domain_strategy

One of prefer_ipv4 prefer_ipv6 ipv4_only ipv6_only.

If set, the requested domain name will be resolved to IP before routing.

If sniff_override_destination is in effect, its value will be taken as a fallback.

udp_timeout

UDP NAT expiration time in seconds, default is 300 (5 minutes).

proxy_protocol

Parse Proxy Protocol in the connection header.

proxy_protocol_accept_no_header

Accept connections without Proxy Protocol header.

detour

If set, connections will be forwarded to the specified inbound.

Requires target inbound support, see Injectable.