howto

Your Debian / Ubuntu Linux box security depends upon access to system services (one of many aspects). For example, you may need to provide a web server (Apache service) to serve web pages. However, if you do not need use a service, you should always turn off all unused services to avoid exploits.

Traditionally, Debian provided various tools to manage services. There are various methods for managing access to system services:
a) /etc/init.d/service
b) rcconf
c) update-rc.d etc

Under Red hat and Centos Linux you can use chkconfig command (ntsysv command) to configure Sys V style init script links. There is also service command to stop / start / restart services.

You can find the memory used by a program (process) by looking into /proc directory or using standard command such as ps or top. However, you must calculate all memory usage by hand i.e. add Shared Memory + mapped file + total virtual memory size of the process + Resident Set Size + non-swapped physical memory used by process.

So how do you find the memory used by a process or program under Linux?

DNS server can be attacked using various techniques such as:
[a] DNS spoofing

[b] Cache poisoning

[c] Registration hijacking

One of the simplest ways to defend is limit zone transfers between nameservers by defining ACL. I see many admin allows BIND to transfer zones in bulk outside their network or organization. There is no need to do this. Remember you don't have to make an attacker's life easier.

Restricting zone transfers with IP addresses in BIND DNS Server

FreeBSD Update is a system for automatically building, distributing, fetching, and applying binary security updates for FreeBSD. This makes it possible to easily track the FreeBSD security branches without the need for fetching the source tree and recompiling. This article talks about using combinations of various tools to keep your FreeBSD system up to date.

Procedure for creating a CSR on postfix MTA is just like web server. You need to use OpenSSL which is a cryptography toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) network protocols and related ryptography standards under Linux / UNIX. To configure postfix SSL SMTP you need 3 files
(a) The private key
(b) Your .crt certificate file
(c) CA certificate

Ipfirewall (ipfw) is a FreeBSD IP packet filter and traffic accounting facility.IPFW is included in the basic FreeBSD install as a separate run time loadable module.

This small howto covers building and installing a custom kernel with IPFW. It also provide a small example on how to setting up the rules for a typical FreeBSD based Apache Web server.

Malware is software designed to infiltrate or damage a computer system without the owner's informed consent. It is a portmanteau of the words "malicious" and
"software". The expression is a general term used by computer professionals to mean a variety of forms of hostile, intrusive, or annoying software or program code.

Setting up a malware blacklist in Postix MTA is quite easy. The Malware Block List is a free, automated and user contributed system for checking URLs for the presence of Viruses, Trojans, Worms, or any other software considered Malware

If you're serious about music or DVDs, at some point you cross the threshold of having more than you can keep track of easily. The box full of index cards has served its purpose; it's time to move on to storing information about your CDs and DVDs in a database.

This might seem like more of a pain than you can stand. What's the point of doing a database when you can just type it all into a spreadsheet, for instance? Well, a spreadsheet is a good start but with a database you get a lot more features, including easily printing custom labels for all those legal backups you’ve made. You could also print out a record of all your movies or music, if you keep notes on them such as summaries, who you’ve loaned them to, and anything else you track.

Almost all new Linux wanna be guru (read as users who want to switch to Linux) asks a question:
I want to switch to Linux completely from Windows XP SP2. Which Linux version will be best - Redhat, SuSE, or other? I use my PC for:

Browsing Internet
Watching DVD / MP3
Writing CD/DVD
I’m also willing to spend a small amount of money if required to purchase Linux version.

Short answer is none. I can’t suggest *distro* name.

Red hat enterprise Linux 5 provides different tools to make changes to Network configuration such as add new card, assign IP address, change DNS server etc. This guide covers configuration using GUI and command line tools. The instructions are compatible with CentOS and Fedora Core Linux.