AdguardTeam/AdGuardHome · error

parsing hardware address: %w

Error message

parsing hardware address: %w

What it means

Converting a stored lease database record to an in-memory lease failed because the HWAddr field is not a parseable MAC address (net.ParseMAC error). The leases.json entries must contain hardware addresses in standard colon/hyphen/dot notation.

Source

Thrown at internal/dhcpd/db.go:72

		//
		// See https://github.com/AdguardTeam/AdGuardHome/issues/2692.
		expiryStr = l.Expiry.Format(time.RFC3339)
	}

	return &dbLease{
		Expiry:   expiryStr,
		Hostname: l.Hostname,
		HWAddr:   l.HWAddr.String(),
		IP:       l.IP,
		IsStatic: l.IsStatic,
	}
}

// toLease converts *dbLease to *dhcpsvc.Lease.
func (dl *dbLease) toLease() (l *dhcpsvc.Lease, err error) {
	mac, err := net.ParseMAC(dl.HWAddr)
	if err != nil {
		return nil, fmt.Errorf("parsing hardware address: %w", err)
	}

	expiry := time.Time{}
	if !dl.IsStatic {
		expiry, err = time.Parse(time.RFC3339, dl.Expiry)
		if err != nil {
			return nil, fmt.Errorf("parsing expiry time: %w", err)
		}
	}

	return &dhcpsvc.Lease{
		Expiry:   expiry,
		IP:       dl.IP,
		Hostname: dl.Hostname,
		HWAddr:   mac,
		IsStatic: dl.IsStatic,
	}, nil
}

View on GitHub (pinned to b41aefbe51)

Solutions

1. Inspect the HWAddr values in the leases file and fix malformed entries to standard MAC format (aa:bb:cc:dd:ee:ff)
2. Delete or back up and remove the leases file to start fresh (leases will be re-acquired)
3. Restore from backup if the DB is corrupted

Example fix

// before
{"HWAddr": "192.168.1.5"}
// after
{"HWAddr": "aa:bb:cc:dd:ee:ff"}

// before loading
for _, dl := range dbLeases {
    if _, err := net.ParseMAC(dl.HWAddr); err != nil { /* skip or fix entry */ }
}

func isValidMAC(s string) bool { _, err := net.ParseMAC(s); return err == nil }

When it happens

Trigger: Loading a leases.db/leases.json where a lease's HWAddr is empty, malformed (wrong digit count, invalid characters), or stored in an unsupported format.

Common situations: Corrupted lease DB after crash or disk issue; hand-edited lease files; lease DB written by an incompatible fork or version.

Related errors

• parsing expiry time: %w
• decoding db: %w
• loading db: %w
• reading db: %w
• resetting dhcpv4 leases: %w

AI-assisted analysis of AdguardTeam/AdGuardHome@b41aefbe51 (2026-08-27). Data as JSON: /api/errors/b4f89d0d5fed52c6. Report an issue: GitHub.