WebConfigurationManager tipado e com valor padrão

int operatorId = WebConfigurationManager.AppSettings.Get<int>("OperatorId");

int operatorIdComDefault = WebConfigurationManager.AppSettings.Get<int>("OperatorId", 1);

public static class NameValueCollectionExtension
{
    public static T Get<T>(this NameValueCollection collection, string key, T defaultValue = default(T)) where T : IConvertible
    {
        var value = collection.Get(key);
        if (value != null)
        {
            return (T)Convert.ChangeType(value, typeof(T));
        }
        return defaultValue;
    }
}

Como configurar um IP primário no Windows Server 2012

Primário:

netsh int ipv4 add address <Interface Name> <ip address> <subnetmask>

Secundários:

netsh int ipv4 add address <Interface Name> <ip address> <subnetmask> skipassource=true

Exemplo:

netsh int ipv4 add address "WAN" 1.1.1.1 255.255.255.0
netsh int ipv4 add address "WAN" 1.1.1.2 255.255.255.0 skipassource=true
netsh int ipv4 add address "WAN" 1.1.1.3 255.255.255.0 skipassource=true
netsh int ipv4 add address "WAN" 1.1.1.4 255.255.255.0 skipassource=true

Referência: http://www.securahosting.com/2013/06/12/how-to-set-a-primary-ip-address-on-windows-server-2012/