How to validate DropDownListFor for values bound with list

How to validate DropDownListFor for values bound with list

I want to validate values in DropDownListFor but its not working. I have
included required script files for client side validation too.
In ViewModel:
public class SearchViewModel
{
public List<MarriageProfile> Profiles { get; set; }
public SearchProfile SearchProfile { get; set; }
}
public class SearchProfile
{
[Required(ErrorMessage="*")]
public SelectList Ages { get; set; }
public string Age { get; set; }
}
In Controller:
var ages = AgeList
.Select(p => new SelectListItem()
{
Text = p.ToString(),
Value = p.ToString()
}).ToList();
SearchViewModel.SearchProfile.Ages = new SelectList(ages, "Text", "Value");
static List<string> AgeList = new List<string>()
{
"18-23",
"23-28",
"28-33",
"33-38",
"38-43",
"43-48"
};
In View :
@Html.DropDownListFor(model => model.Age, Model.Ages, "--Select One--",
new { @class = "form-control" })
@Html.ValidationMessageFor(m => m.Age)
On submitting the form , no client or server side validation working for
the dropdownlist above. What could be wrong with the code?