er of IP hops that a packet is allowed to
travel through. Each router or gateway that forwards a packet decrements the
TTL. If the TTL is decremented to 0 by a router, it will not be forwarded.
Changing TTL values is typically done for network probes or when multicasting.</p>
<p>The <code>ttl</code> argument may be between between 1 and 255. The default on most systems
is 64.</p>
<p>This method throws <code>EBADF</code> if called on an unbound socket.</p>
<h3><code>socket.unref()</code><span><a class="mark"