Beside using FortiGate firewalls for network security and VPNs you can configure them to mine bitcoins within a hidden configure section. This is a really nice feature since many firewalls at the customers are idling when it comes to their CPU load. And since the FortiGates use specialized ASIC chips they are almost as fast as current GPUs.
If you have not yet used those hidden commands, here we go:
You must register yourself on a mining pool first in order to use those login credentials within your FortiGate. For example, I am using slushpool.com. It uses the stratum mining protocol on port 3333 to connect to the server. These are the basic commands for using a FortiGate as a Bitcoin Miner:
config system bitcoin-mining
set algo sha256d
set url "stratum+tcp://eu.stratum.slushpool.com"
set port 3333
set username webernetz
set password ThisIsYourPassword
set usage idle
All options should be quite obvious. Of course you must specify your username and password as well as the URL from your mining pool. Instead of idle you can set the usage to max. This configures whether the FortiGate should only mine bitcoins when the CPUs are in idle state, or constantly ongoing (max).
If the FortiGate is actively mining bitcoins, its LEDs on the front turn purple. This is a nice feature as well since you can immediately see which units are currently in use in your pool. I am currently using a single FG-100D for mining in my lab:
However, note that the CPU load immediately increases to about 100 % as you can see in this graph from my monitoring server (MRTG + RRDtool):