Admin Magazine

Internet users typically reveal their IP addresses, and this lets companies compile a profile of your Internet activities. Tor and Privoxy can help protect your privacy.

If you need a tool for filtering protocols that doesn’t depend on the port, try L7, an IPTables patch that operates through regular expressions.

Networks often require very accurate timekeeping. The Network Time Protocol provides the time with precision.

It is quite easy to take a TCP connection down using a RST attack, and this risk increases with applications that need long-term connections, such as VPNs, DNS zone transfers, and BGP. We’ll describe how a TCP attack can happen, and we’ll show you some simple techniques for protecting your network.

Permanent mobile Internet access might sound like a nightmare for some, but for others it is a dream come true. All you need is Linux and a fairly recent mobile phone.

Despite the cyclical disruptions so typical of LUG meetings, our intrepid columnist, Charly, reveals how he set the system time in spite of a blocked NTP port.

Socks is a universal proxy protocol for TCP and UDP that allows internal hosts to securely pass the firewall and authenticates users. This article describes the latest version of the Socks proxy protocol and shows how to implement it.