How about this... ( untested, just something that came to mind )

   do{
       ## note that some versions of ping keep pinging
       ## forever... you may need to use a flag like -c
       ## ( if available ) to limit the number of tries
       system( "ping your.ip.address" );
   } while( $? != 0 );
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I like the Net::Ping idea by shockme as well, except it won't let you use icmp requests unless you make your script setuid, which although understandable, really really sucks