Simulate a DNS DDoS Attack
--------------------------

1. Open the SSH session to the victim server and ensure the top utility
   is running.

2. | Once again, attack your DNS server from the attack host using the
     following syntax:
   | ``dnsperf -s 10.20.0.10 -d queryfile-example-current -c 20 -T 20 -l 30 -q 10000 -Q 10000``

3. On the server SSH session running the top utility, notice the CPU
   utilization on your server remains in a range that ensures the DNS
   server is not overwhelmed.

4. After the attack, navigate to **Security** > **Event Logs** > **DoS**
   > **DNS Protocol**. Observe the logs to see the mitigation actions
   taken by the BIG-IP. Be sure to scroll right…

   |image61|

.. |image61| image:: /_static/class1/image59.png
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   :height: 2.78542in