====== Networking - ASN (Autonomous System Number) - Use an ASN to Create an IP Blocklist ======

For example to create a blocklist of IP addresses used by FaceBook:

<code bash>
whois -h whois.radb.net -- '-i origin AS32934' | grep ^route | grep -v route6 | cut -d" " -f7 > /var/www/block_lists/facebook.txt
</code>

<WRAP info>
**NOTE:**  As IP addresses can change often in an ASN, it is important to update the blocklist regularly.  

A cron job each day is suggested.

If used on pfSense, make a URL table alias that points to that facebook.txt file, then use the alias in rules as needed.

</WRAP>