Strategy: Defense in Depth
Layers of protection block different kinds of threats and may provide backup if one layer fails.
Hardware router
- Using NAT1 masks IP address from port scans.
- Blocks unsolicited incoming communications.
- Does not protect against most malware, such as Trojan horses, viruses, e-mail worms, and spyware.
Software firewall
- Prevents backdoor apps, Trojan horses, and unwanted applications from sending data from the PC.
- Protects a laptop on public wired and wireless networks.
- Can block some malware, but can't remove it.
Antispam software
- Blocks deceptive e-mail scams (phishing schemes).
- Reduces e-mail sorting fatigue, so users are less likely to accidentally activate an e-mail-borne virus in haste.
Antivirus software
- Protects against known worms, viruses, and Trojan horses but is less effective against new infectors.
- Systems are still vulnerable to infiltration from adware, spyware, and browser hijackers.
Anti-spyware software
- Protects against adware, browser hijackers, spyware, tracking cookies, and other Internet parasites.
1The Network Address Translation Internet standard allows LANs to use different sets of IP addresses for internal and external traffic.
