Paulo Bu's questions

I'm having problems understanding how RewriteCond directive works. So far, it's pretty clear that it compares to strings to apply a RewriteRule. I have this file:

<IfModule rewrite_module>
    RewriteEngine on
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteRule ^(.*)$ app_dev.php
</IfModule>

This works for me but I don't know why it works. So far in the RewriteCond directive I understand:

if the value of REQUEST_FILENAME is NOT a file in the hard drive then allow the rule

This doesn't have sense becouse app_dev.php after substituting is a file in the hard drive. Anyways, could someone enlighten me with this issue? I am having a very harsh time figuring out how this works.

I need to know if there is a way to automatically install Windows XP on multiple computers (about 50). Something like creating a "bat" file or some sort of script file where I would write the configuration I need and then just power on the computers and Windows will install on all the computers. I think this problem may be a very common one and I googleed it, but I didn't like any of the solutions. It would be great if I could configure automatically the computer's name and IP address, but I think this may be too much to ask.

that's it, is there a way to discover a network topology at level 3 or IP level, i mean, i want to build a program that maps the different networks that are reachable from mine and where the routers are. any ideas? thanks in advance ike

i need to get the route table from a router and i think snmp is capable of doing that, any idea of a good snmp client to accomplish this, or, any idea not involving snmp to solve this problem? thanks in advance