code: func skipIPAddr(ip net.IP) bool {
  	switch {
  	case ip.IsLinkLocalMulticast():
  		fallthrough
  	case ip.IsLinkLocalUnicast():
  		fallthrough
  	case ip.IsLoopback():
  		fallthrough
  	case ip.IsMulticast():
  		return true
  	}
  	return false
  }
docs: // skipIPAddr defines the set of criteria that buildAndSelectGuestIPs uses to
  // check to see if it needs to skip an IP address.