AdguardTeam/AdGuardHome · error

cannot get network interfaces: %w

Error message

cannot get network interfaces: %w

What it means

While expanding wildcard DNS bind addresses (0.0.0.0/::) into concrete addresses for the status API, enumeration of network interfaces via aghnet.GetValidNetInterfacesForWeb failed. The wrapped error comes from net.Interfaces.

Source

Thrown at internal/home/control.go:57

// dst.  It also adds the IP addresses of all network interfaces if src contains
// an unspecified IP address.
func appendDNSAddrsWithIfaces(dst []string, src []netip.Addr) (res []string, err error) {
	ifacesAdded := false
	for _, h := range src {
		if !h.IsUnspecified() {
			dst = appendDNSAddrs(dst, h)

			continue
		} else if ifacesAdded {
			continue
		}

		// Add addresses of all network interfaces for addresses like
		// "0.0.0.0" and "::".
		var ifaces []*aghnet.NetInterface
		ifaces, err = aghnet.GetValidNetInterfacesForWeb()
		if err != nil {
			return nil, fmt.Errorf("cannot get network interfaces: %w", err)
		}

		for _, iface := range ifaces {
			dst = appendDNSAddrs(dst, iface.Addresses...)
		}

		ifacesAdded = true
	}

	return dst, nil
}

// collectDNSAddresses returns the list of DNS addresses the server is listening
// on, including the addresses on all interfaces in cases of unspecified IPs.
// extTLSConf must not be nil.
func collectDNSAddresses(extTLSConf *aghtls.ExtendedTLSConfig) (addrs []string, err error) {
	if hosts := config.DNS.BindHosts; len(hosts) == 0 {
		addrs = appendDNSAddrs(addrs, netutil.IPv4Localhost())

View on GitHub (pinned to b41aefbe51)

Solutions

1. Check the wrapped error for the syscall-level cause
2. In containers, ensure adequate network namespace visibility (avoid --network none with wildcard binds, run with normal netns)
3. Restart the service if the failure was transient interface churn
4. Bind DNS to explicit IPs instead of 0.0.0.0 to bypass interface enumeration

Example fix

# before
dns:
  bind_hosts: [0.0.0.0]
# after
dns:
  bind_hosts: [192.168.1.10]

// Catch and degrade: report status without expanded addresses
if err != nil { addrs = []string{"unavailable"} }

When it happens

Trigger: GET /control/status when DNS bind hosts contain wildcard addresses and the OS fails to enumerate interfaces (net.Interfaces error).

Common situations: Containerized environments with restricted /sys or netlink, heavily chrooted processes, interfaces disappearing mid-enumeration, OS-level networking stack issues.

Related errors

• collecting dns addresses: %w
• creating dns server: %w
• starting dnssvc: %w
• parsing json time: %w
• json time is nil

AI-assisted analysis of AdguardTeam/AdGuardHome@b41aefbe51 (2026-08-27). Data as JSON: /api/errors/0f9f4347555c3523. Report an issue: GitHub.