This code will help to align the elements with three columns in lg, and md mode, two column in sm mode, and single column is xs mode
<div class="row">
<div ng-repeat="oneExt in configAddr.ext">
<div class="col-xs-12 col-sm-6 col-md-4 col-lg-4">
{$index+1}}.
<input type="text" name="macAdr{{$index+1}}"
id="macAddress" ng-model="oneExt.newValue" value=""/>
</div>
</div>