title: How to simulate a point-to-point network with failover in NS3?
body: <p>How to build a point-to-point network with failover backup links using NS3? For example, between each pair of connected points, there are 2 links, the primary link which is active by default and a secondary link with different parameters (data rate, delay, etc) which is blocked. On failure of the primary link the secondary link is used.</p>