Answers for "bootstrap 4 fixed navbar"

NavBar Bootstrap v4 Fix

<nav class="navbar navbar-expand-sm navbar-dark fixed-top bg-dark">
  <div class="container">
    <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
    </button>
    <a class="navbar-brand" href="/">Application name</a>
    <div class="navbar-collapse collapse" id="navbarSupportedContent">
      <ul class="nav navbar-nav mr-auto">
        <li class="nav-item"><a href="/" class="nav-link">Home</a></li>
        <li class="nav-item"><a href="/Home/About" class="nav-link">About</a></li>
        <li class="nav-item"><a href="/Home/Contact" class="nav-link">Contact</a></li>
      </ul>

      <ul class="nav navbar-nav navbar-right mr-auto">
        <li class="nav-item"><a href="/Account/Register" id="registerLink" class="nav-link">Register</a></li>
        <li class="nav-item"><a href="/Account/Login" id="loginLink" class="nav-link">Log in</a></li>
      </ul>

    </div>
  </div>
</nav>

fixed-top navbar bootstrap

<nav class="navbar navbar-expand-sm bg-light fixed-top">

bootstrap navbar fixed top

<section id="headnev" class="navbar navbar-fixed-top">

bootstrap nav

<ul class="nav nav-tabs" id="myTab" role="tablist">
  <li class="nav-item">
    <a class="nav-link active" id="home-tab" data-toggle="tab" href="#home" role="tab" aria-controls="home" aria-selected="true">Home</a>
  </li>
  <li class="nav-item">
    <a class="nav-link" id="profile-tab" data-toggle="tab" href="#profile" role="tab" aria-controls="profile" aria-selected="false">Profile</a>
  </li>
  <li class="nav-item">
    <a class="nav-link" id="contact-tab" data-toggle="tab" href="#contact" role="tab" aria-controls="contact" aria-selected="false">Contact</a>
  </li>
</ul>
<div class="tab-content" id="myTabContent">
  <div class="tab-pane fade show active" id="home" role="tabpanel" aria-labelledby="home-tab">...</div>
  <div class="tab-pane fade" id="profile" role="tabpanel" aria-labelledby="profile-tab">...</div>
  <div class="tab-pane fade" id="contact" role="tabpanel" aria-labelledby="contact-tab">...</div>
</div>