The following code shows how to align navbar to bottom.
<!DOCTYPE html>
<html lang="en">
<head>
<link rel="stylesheet"
href="http://netdna.bootstrapcdn.com/bootstrap/3.0.3/css/bootstrap.min.css">
<link rel="stylesheet"
href="http://netdna.bootstrapcdn.com/bootstrap/3.0.3/css/bootstrap-theme.min.css">
<script type="text/javascript"
src="http://code.jquery.com/jquery.min.js"></script>
<script
src="http://netdna.bootstrapcdn.com/bootstrap/3.0.3/js/bootstrap.min.js"></script>
</head><!--from w ww . j av a 2 s .co m-->
<body>
<nav role="navigation"
class="navbar navbar-default navbar-fixed-bottom">
<!-- Brand and toggle get grouped for better mobile display -->
<div class="navbar-header">
<button type="button" data-target="#navbarCollapse"
data-toggle="collapse" class="navbar-toggle">
<span class="sr-only">Toggle navigation</span> <span
class="icon-bar"></span> <span class="icon-bar"></span> <span
class="icon-bar"></span>
</button>
<a href="#" class="navbar-brand">Brand</a>
</div>
<!-- Collection of nav links and other content for toggling -->
<div id="navbarCollapse" class="collapse navbar-collapse">
<ul class="nav navbar-nav">
<li class="active"><a href="#">Home</a></li>
<li><a href="#">Profile</a></li>
<li><a href="#">Messages</a></li>
</ul>
<ul class="nav navbar-nav navbar-right">
<li><a href="#">Login</a></li>
</ul>
</div>
</nav>
</body>
</html>