AdguardTeam/AdGuardHome · critical

validating udp ports: %w

Error message

validating udp ports: %w

What it means

The UDP port set (DNS-over-QUIC and implicitly other UDP listeners) failed validation — duplicate or invalid port values. Companion of the TCP port validation.

Source

Thrown at internal/home/config.go:783

	addPorts(udpPorts, udpPort(config.DNS.Port))

	if config.TLS.Enabled {
		addPorts(
			tcpPorts,
			tcpPort(config.TLS.PortHTTPS),
			tcpPort(config.TLS.PortDNSOverTLS),
			tcpPort(config.TLS.PortDNSCrypt),
		)

		// TODO(e.burkov):  Consider adding a udpPort with the same value when
		// we add support for HTTP/3 for web admin interface.
		addPorts(udpPorts, udpPort(config.TLS.PortDNSOverQUIC))
	}

	if err = tcpPorts.Validate(); err != nil {
		return fmt.Errorf("validating tcp ports: %w", err)
	} else if err = udpPorts.Validate(); err != nil {
		return fmt.Errorf("validating udp ports: %w", err)
	}

	if !filtering.ValidateUpdateIvl(config.Filtering.FiltersUpdateIntervalHours) {
		config.Filtering.FiltersUpdateIntervalHours = 24
	}

	if len(config.Users) == 0 {
		l.WarnContext(ctx, "no users in the configuration file; authentication is disabled")
	}

	if config.Language != "" && !allowedLanguages.Has(config.Language) {
		l.WarnContext(ctx, "unsupported language", "lang", config.Language)

		// Clear the language so the frontend can use the client's browser
		// language.
		config.Language = ""
	}

View on GitHub (pinned to b41aefbe51)

Solutions

1. Set port_dns_over_quic to a valid unused UDP port (default 853/784)
2. Ensure it doesn't duplicate other UDP services in the config
3. Restart and confirm the wrapped validation error is gone

Example fix

# before
port_dns_over_quic: 99999
# after
port_dns_over_quic: 853

if cfg.TLS.PortDNSOverQUIC < 1 || cfg.TLS.PortDNSOverQUIC > 65535 {
    return errors.New("invalid quic port")
}

When it happens

Trigger: port_dns_over_quic set to an invalid value (0, >65535) or colliding with another UDP listener per udpPorts.Validate().

Common situations: Hand-edited config with a bad port_dns_over_quic, copying configs between instances without adjusting ports, typos.

Related errors

• validating tcp ports: %w
• dns.bind_hosts at index %d is not a valid ip address
• networksetup failed to set dns servers: %w
• found no dns servers in %s
• writing conf: %w

AI-assisted analysis of AdguardTeam/AdGuardHome@b41aefbe51 (2026-08-27). Data as JSON: /api/errors/2d322557b8d48729. Report an issue: GitHub.