netbirdio/netbird · error

assign addr: %w

Error message

assign addr: %w

What it means

freebsd link.AssignAddr executes `ifconfig <name> inet <ip> netmask <mask>` (mask pre-formatted as 0x%08x in wg_link_freebsd.go) and wraps a non-zero exit as 'assign addr'. The companion IPv6 assignment (an explicit `ifconfig <name> inet6 <addr>` plus the link-local add inside setAddr) is deliberately soft: failures are logged and IPv6 cleared, continuing v4-only. The IPv4 assignment wrapped here is fatal.

Source

Thrown at client/iface/device/wg_link_freebsd.go:74

	}

	return nil
}

func (l *wgLink) assignAddr(address *wgaddr.Address) error {
	link, err := freebsd.LinkByName(l.name)
	if err != nil {
		return fmt.Errorf("link by name: %w", err)
	}

	prefixLen := address.Network.Bits()
	maskBits := uint32(0xffffffff) << (32 - prefixLen)
	mask := fmt.Sprintf("0x%08x", maskBits)

	log.Infof("assign addr %s mask %s to %s interface", address.IP, mask, l.name)

	if err := link.AssignAddr(address.IP.String(), mask); err != nil {
		return fmt.Errorf("assign addr: %w", err)
	}

	if address.HasIPv6() {
		log.Infof("assign IPv6 addr %s to %s interface", address.IPv6String(), l.name)
		cmd := exec.Command("ifconfig", l.name, "inet6", address.IPv6String())
		if out, err := cmd.CombinedOutput(); err != nil {
			log.Warnf("failed to assign IPv6 address %s to %s, continuing v4-only: %s: %v", address.IPv6String(), l.name, string(out), err)
			address.ClearIPv6()
		}
	}

	if err := link.Up(); err != nil {
		return fmt.Errorf("up: %w", err)
	}

	return nil
}

View on GitHub (pinned to 93e97f4bf1)

Solutions

1. Check debug logs for the ifconfig stderr line captured with this error
2. Validate the IP and computed netmask before starting the agent
3. Confirm privileges and that the interface exists
4. Retry after cleaning any partial configuration from earlier attempts

// validate address and mask before handing them to ifconfig
if !ip.IsValid() || bits < 0 || bits > 32 {
    return fmt.Errorf("invalid IPv4 assignment %s/%d", ip, bits)
}

if err := link.AssignAddr(ip, mask); err != nil {
    log.Debugf("ifconfig stderr: %v", err)
    // invalid pair, missing interface, or privilege issue: fix cause, then retry
    return err
}

When it happens

Trigger: Invalid IP or netmask string passed to ifconfig, interface missing at assignment time, insufficient privileges to set an address.

Common situations: Misformed address/netmask received from management, interface churn between creation and configuration, restricted jails.

Related errors

• link by name: %w
• set interface addr: %w
• error assigning ip: %s
• up: %w
• link by name: %w

AI-assisted analysis of netbirdio/netbird@93e97f4bf1 (2026-08-16). Data as JSON: /api/errors/06cfcd45b9941cff. Report an issue: GitHub.