netbirdio/netbird · error

add output sport notrack rule: %w

Error message

add output sport notrack rule: %w

What it means

Error "add output sport notrack rule: %w" thrown in netbirdio/netbird.

Source

Thrown at client/firewall/iptables/manager_linux.go:564

//     dst=127.0.0.1:proxyPort
//     Matched by: dport=proxyPort
//
// Rules are cleaned up when the firewall manager is closed.
func (m *Manager) SetupEBPFProxyNoTrack(proxyPort, wgPort uint16) error {
	m.mutex.Lock()
	defer m.mutex.Unlock()

	if !m.rawSupported {
		return fmt.Errorf("raw table not available")
	}

	wgPortStr := fmt.Sprintf("%d", wgPort)
	proxyPortStr := fmt.Sprintf("%d", proxyPort)

	// Egress rules: match outgoing loopback UDP packets
	outputRuleSport := []string{"-o", "lo", "-s", "127.0.0.1", "-d", "127.0.0.1", "-p", "udp", "--sport", wgPortStr, "-j", "NOTRACK"}
	if err := m.ipv4Client.AppendUnique(tableRaw, chainNameRaw, outputRuleSport...); err != nil {
		return fmt.Errorf("add output sport notrack rule: %w", err)
	}

	outputRuleDport := []string{"-o", "lo", "-s", "127.0.0.1", "-d", "127.0.0.1", "-p", "udp", "--dport", wgPortStr, "-j", "NOTRACK"}
	if err := m.ipv4Client.AppendUnique(tableRaw, chainNameRaw, outputRuleDport...); err != nil {
		return fmt.Errorf("add output dport notrack rule: %w", err)
	}

	// Ingress rules: match incoming loopback UDP packets
	preroutingRuleWg := []string{"-i", "lo", "-s", "127.0.0.1", "-d", "127.0.0.1", "-p", "udp", "--dport", wgPortStr, "-j", "NOTRACK"}
	if err := m.ipv4Client.AppendUnique(tableRaw, chainNameRaw, preroutingRuleWg...); err != nil {
		return fmt.Errorf("add prerouting wg notrack rule: %w", err)
	}

	preroutingRuleProxy := []string{"-i", "lo", "-s", "127.0.0.1", "-d", "127.0.0.1", "-p", "udp", "--dport", proxyPortStr, "-j", "NOTRACK"}
	if err := m.ipv4Client.AppendUnique(tableRaw, chainNameRaw, preroutingRuleProxy...); err != nil {
		return fmt.Errorf("add prerouting proxy notrack rule: %w", err)
	}

View on GitHub (pinned to 93e97f4bf1)

When it happens

Trigger: Thrown at client/firewall/iptables/manager_linux.go:564 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of netbirdio/netbird@93e97f4bf1 (2026-08-16). Data as JSON: /api/errors/c642ffdf021d54fb. Report an issue: GitHub.