The Radius protocol is typically used to authenticate users in dial-up scenarios. But Radius is also useful in LAN environments: in combination with 802.1X, Radius forces users to authenticate at a low level before the switch opens up a port.

On vacation we may be happy just to check the position of the sun,but computers need a more accurate measure of time. Luckily, there are atomic clocks that can receive time signals by radio and off the Internet.

Wireless networks are practical but dangerous at the same time.WEP encryption is unlikely to stop an attacker. But help is at hand in the form of add-on security measures such as an encrypted OpenVPN tunnel.

Firewalls are typically implemented as routers,but it doesn’t have to be that way. Bridging packet filters have a number of advantages,and you can add them to your network at a later stage without changing the configuration of your network components.

When users think about their workstations at home, they often forget about security. But danger is out there,waiting to pounce on the unsuspecting. Shorewall helps everyday Linux users keep the intruders away.

Firewalls are becoming evermore sophisticated. Luckily, the tools for managing firewalls are becoming simpler and more accessible for ordinary users