 most
functions and methods accept both  IP addresses and host names. In  case a
host name is given, the  library  queries the  system's  resolver  and
tries  the main IP address returned. Note that direct use of IP addresses
is more efficient, of course. The 
<a href=dns.html#toip><tt>toip</tt></a> 
and <a href=dns.html#tohostname><tt>tohostname</tt></a> 
functions from the DNS module are provided to convert between host names and IP addresses. 
</p>

<p>
Together, these changes make network programming in