Well, that looks good to me. In the "We have a problem" section, you would be best to put some reasons in using the values $in and $out so you can see what's happening, such as:-

Code:

...
...
if [ $in -ne $out ]
then
   echo "We have a problem.  I sent $in, but received $out."
else
...
...

The if statement

Code:

if [ $in -ne $out ]

is a numeric comparison. The operator -ne is "Not Numerically Equal" but causes trouble if you try to use it with alphanumerics on many systems. So, if the packets sent in are not equal to the packets got out, then you get the warning message. That's the logic.



Robin
Liverpool/Blackburn
UK