The presence of a redundancy protocol, a firewall, or a VPN tunnel makes your network infrastructure more secure. Or does it? Security countermeasures are only as good as their installation and support specialists. A redundancy protocol that would allow an impostor to spoof your gateway address, a firewall that can be bypassed, or a VPN tunnel that can be cracked (or is not secure at all) are gaping holes in your network and disasters waiting to happen. Even more, these are sly gaping holes, since the very presence of the safeguards mentioned creates a false sense of security and invincibility.
Underestimating your enemy and overestimating your defenses is the worst thing that may happen on a battlefield, digital or not. Follow through with the hardening recommendations presented in this chapter and don't let it happen to you.