Custom font not working in ie

In Internet Explorer 8 and earlier, the URL must point to an Embedded OpenType (EOT) file (.eot or .ote format). No other font formats are supported.

Below css will work in all browsers

@font-face {

    font-family: "customfontname";

    src: url('customfontname.eot?#iefix') format('embedded-opentype'), 

         url('customfontname.woff') format('woff'), 

         url('customfontname.ttf')  format('truetype'),

         url('customfontname.svg#customfontname') format('svg'),    

         url("../customfontname.woff2") format("woff2");

    font-weight: normal;

    font-style: normal;

}