Spammers charge real money for their dubious services, and hundreds of advertisers are willing to pay. We’ll show you some innovative techniques for controlling and containing spam, including strategies for slowing down spam bots, keeping spammers from getting your address, and separating spam from legitimate email.

If you think your systems are too obscure for an attacker to worry about, think again. Today’s intruders are happy for any victim.

Commercial surveillance systems are expensive and typically involve maintenance agreements. I thought there must be a low-budget alternative.

A genuine multitasking system like Linux runs many processes concurrently. Programs must compete for data access. Assigning locks to files ensures exclusive access and prevents the possibility of data.

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.

Data always seems to get lost at exactly the wrong moment, but the right backup strategy can help you restore those missing files.

When backup jobs become too challenging for a script, the daemon-based free backup tool Bacula may be the answer.

System admins routinely refer to documentation for help with obscure command line options. In this month’s Admin Workshop, we examine the programs and formats behind the command line documentation you read everyday.