Carla Schroder

Linux’s venerable file and user permissions system is solid and dependable, but not very flexible, unfortunately. For users to share access to a particular document or resource, they must all be in the same group. It’s an all-or-nothing deal, as all users within a group have all the same rights, which is most inconvenient when […]

In part 1 we looked at a simple setup for creating and sharing a dial-up Internet connection. Today we’ll learn how to build a dial-in server. A dial-in server is useful for remote system administration, remote user access, or building a low-cost WAN. A Linux dial-in server can serve as a gateway for both Linux […]

Sometimes it seems that the world has moved entirely to DSL, cable, and other forms of high-speed networking. But the reality is it hasn’t — most of the world is on dial-up, and even in the US the majority of Internet users are still on dial-up. Even in areas where high-speed access is available, dial-up […]

Carefully constructing walls and moats to keep the bad guys out of our systems is an everyday task. It’s equally important to build walls and moats to keep them in, should they successfully penetrate our defenses. Let’s go ahead and review why filtering outbound traffic is so critical, as I still encounter decision makers who […]

In a previous article we introduced you to Tripwire, a very useful security tool for your network installation. In this article, we’ll move to the specifics of installing and configuring Tripwire — and more specifically, we’ll tell you how to install it a sensible policy file, which is really the heart of Tripwire. This article […]

Ethernet cabling is generally of high quality, network faults are more likely to lie elsewhere. Software glitches, such as configuration problems, and user shenanigans are the primary causes of network problems (insert favorite horror story here). However there are times when the cabling itself is at fault. With the right tools, testing is quick and […]

Last week we looked at the broad strokes of Tinydns, a replacement for BIND you can drop into anything from a home LAN to an enterprise deployment. This week it’s time to get in-depth with configuration, so let’s start off with some clarification of terminology. DNS is confusing enough, and BIND is the Lord of […]

First of two parts DNS admins rejoice, for thy long years of torment are over. No more shall BIND bewitch and betray thee, for there is a new kid on the block: Tinydns. No discussion of Tinydns is complete without mention of its author, D. J. Bernstein. Professor Bernstein is a very smart mathematician and […]

Adding a honeypot to your arsenal can be a big boost to your network’s security, both in distracting malicious users and learning how the garden variety script kiddy or cracker thinks. First, a few terms: Crackers are bad guys bent on criminal mischief. Hackers are computer nerds who create cool things. Crackers destroy. Hackers build. […]

FreeSCO’s nicest feature is the sensible default firewall configuration. Log into the setup screen, and select a) Advanced Settings. To activate the built-in firewall, select 11, On/Off NAT/Firewall.: Enable IP masqerade: y. If the nodes on your LAN have routable IP addresses, this won’t work- otherwise it must be enabled. Follow the steps in Part […]

Build A Router With A 386 And A Floppy Disk by Carla Schroder FreeSCO is a single-floppy-disk router for networks with static routing. It is a good choice for lighter routing chores, when a full-blown heavy-duty commercial router is much too much. It makes a nice Internet gateway for a home or small office network. […]