Linux in a Nutshell 5th Edition Review

Linux in a Nutshell, 5th Edition By: Ellen Siever, Aaron Weber, Stephen Figgins, Robert Love, Arnold Robbins, et al. is a fantastic reference book for both newbies to Linux or system administrators that have 20+ years of experience. The book is published by O'Reilly Media, which is the leader in great and easy to read technical book. The book is a massive 944 pages. Two-thirds of which is commands to use with linux and a detail and examples of most if not all the options with that command. If you are reading a forum post and want to find the truth about what that command is doing to the system then use this book to find that out so you want be left with possible deleting your system. The list of commands are in alphabetical order so they are easy to thumb to the correct command. It is great to learn about the commands. I think adding the commands in this kind of list and format is the best thing about the book. I will use that section for years to come. 

Also if you want to know about how to set up different services or servers running Linux you can with this book also. You can learn about DNS/BIND, SSH, file sharing, networking and a lot more within the other chapters of the book. 

My only caution with this book is that it is for the person wanting to become proficient in the use of the command line. It is not for the typical user unless you love the command line. If you are a casual user then I would recommend an Ubuntu book by O'Reilly. There are no graphics in the book, so you will know the command line by the time you study and read this book. Also you cannot understand the command line unless you use it day in and day out.

I give this book 4 out of 5 Penguins just because I wished they would have given more examples and covered more administration topics and expanded on them. But it is still a wonderful book and reference tool. It will stay next to me and my computer.

TV On the Desktop

I have been using Hulu Desktop. It is a new product from www.hulu.com. It brings TV, movies, news, and trailers to watch all in one place without searching on-line for the broadcasts. You can watch clips or in most cases full episodes. This is also a great solution if you have a MythTV solution to your television watching. MythTV is a linux based solution sort of like Windows Media Center, except Myth provides a lot more functionality than Myth does.

Back to Hulu Desktop...

Hulu Desktop allows you to control the screen either with your remote control or with the keyboard, which you would only need your control if it was part of a MythTV solution. Hulu also provides only limited 30 second commercials which are non-obtrusive to the user. The commercial time gives you time to take a break without pausing the shows.

You can edit your profile, subscribe to "channels", and add friends and also discuss shows and offer your opinions on what you thought of the shows. Adding friends and all brings a social networking aspect to whole site and desktop experience.

Check it out I highly recommend it for everyone. This is a great step towards letting go of the cable company or satellite company. People want to watch the shows they want to watch when they want to watch it. Hulu allows that. You get to choose the shows to watch and don't have to record anything any more.

Let me know by leaving a comment if you have looked at it, and what you think. It is availible for Windows, MAC, and Linux.

New Ubuntu

I downloaded the new Ubuntu 9.10 Linux operating system. It is a wonderful operating. It loads and install super fast. It has new features and improvements over the previous versions. This version includes a Software Store see Figure 1. They have taken out some software such as Pidgin and included Empathy as the default IM/Chat program, but the good thing about free and open source software is that if you miss the old programs then you can always get those programs back and re-download them through the synaptic package manager.

Ubuntu also seems to run faster at both start-up and shut-down. They have also updated some of the themes and background images for the desktop which is wonderful. The install looked more professional. While installing Ubuntu I can tell that it is becoming a more mature operating system. I really look forward to the long-term support edition and the future of Ubuntu.

I can tell that Ubuntu is trying to go head-to-head with Microsoft and Apple. It is no accident that Microsoft and Apple both released their operating systems around Ubuntu's normal release. Ubuntu releases an OS every 6-months in April and October.

Passwords: First Step in Insecurity

It is very hard to come up with a good password. Especially if you don't want you site or data accessed. Why do you think that is? The answer is simple if you take the time and make a truly random password it is so complicated that most people can't remember the password, and they write it down and keep the password under their keyboard, on their monitor, or somewhere close to their workstation. This is a BIG NO NO!!! This goes back to the #1 rule of Security: If people have access to your machine then no security measure you take will make you secure. So it is very important that you take the right physical security precautions and secure your work area.

But I know from experience that know matter how much I talk about not writing passwords down you will still do it. If you do write it down then take some password security precautions and at least keep it secure. My advise is to not use passwords alone. Use what in the security world we call 3-forms of authentications: What you have? What you know? and Who you are?

What you know, are things like passwords, security questions, personal information that you may know. What you have, are things such as flash drive or tokens, PDAs, and mobile device. Who you are include bio tech, such as thumb prints, retina scans, and face recognition.

Steps to Secure Passwords

• More than 8 characters long
• Mix of alphanumeric, numeric, and special symbols ($,%,^,@,&,!,?)
• Not words in dictionaries
• Not names or common words

If you combined your extra secure password with what you have such as a flash drive and a simple to use password manager such as KeePass Password Safe Portable found at http://portableapps.com/apps/utilities/keepass_portable

With this utility you can set-up a list of websites that you are a member of and have one really strong random password to protect the data within the program to be accessed.

I look forward to your comments and questions.

Getting Caught with Your Ports Down!!!

What is port scanning? It is like a thief going through your neighborhood and checking every door and window on each house to see which are locked. Port scanning software simply sends out a request to connect to the target computer on each port sequentially and makes a note of which ports responded or seem open to more in-depth probing.

Port scanning can be done with malicious intent, the intruder would generally prefer to go undetected. Network security applications can be configured to alert administrators if they detect connection requests across a broad range of ports from a single host. To get around this the intruder can do the port scan in strobe or stealth mode. Strobing limits the ports to a smaller target set rather than blanket scanning all 65,536 ports. Stealth scanning uses techniques such as slowing the scan.

There are a number of different methods to perform the actual port scans as well as tricks to hide the true source of port scan.

You must find the right balance between network performance and network safety. You could monitor for SYN scans by logging any attempt to send a SYN packet to a port tat isn't open or listening. A SYN scan is a type of TCP scanning that is also known as a "half-open scanning" because it does not open a full TCP connection.

You must ensure you have approval of all the necessary people before port scanning otherwise you may be on the wrong side of the law. Once you find out what ports respond as being open by port scanning your own network you can begin to work on determining whether it is necessary for those ports to be open to outside traffic.

Types of Port Scans Include

• Vanilla: An attempt to connect to all 65,536 ports
• Strobe: An attempt to connect to only selected ports (typically under 20)
• Stealth Scan: Several techniques for scanning that attemp to prevent the request for connection being logged; uses SYN scan FIN scans or other techniques to prevent logging of the scan.
• FTP Bounce: Scan attempts that are directed through an FTP server to disguise the cracker's location.
• Fragmented Packets: Scans by sending packet fragments that can get through simple packet filters in a firewall.
• UDP: Scans for open UDP ports.
• Sweep: Scans the same port on a number of computers.

Tool Used to Perform Port Scanning

NMap (Network Mapper) is a popular free open source software used to port scan. It is a utility for network exploration or security auditing. You can scan a range of IP addresses and ports and find out what an attacker would see if they were to port scan your network. NMap allows great flexibility and control of almost every aspect of the scan and perform various types of port scans to fit your needs.

NMap was designed to rapidly scan large networks, but works find against a single host NMap is:

• Flexible: Supports dozens of advanced techniques for mapping out networks filled with IP filters, firewalls, routers, and other obstacles.
• Powerful: Used to scan huge networks of literally hundreds of thousands of machines.
• Portable: Most operating systems are supported, including: Linux, Microsoft Windows, FreeBSD, Open BSD, Solaris, IRIX, Mac OS X, HP-UX, NetBSD, Sun OS, Amiga, and more.
• Easy: You can start out as simply as nmap-v-A targethost. Both traditional command line and graphical (GUI) versions are available to suit your preference.
• Free: It comes with full source code.
• Well Documented
• Supported
• Popular

Network Modeling

The OSI Model used in discussing and explaining networking concepts at high levels, and also when describing network problems and troubleshooting problems. For a more practical look at the structure a network administrators use the TCP/IP Model.

The OSI Model is a theroritical representation of how a network works.

OSI Model
7-- Application Layer
6-- Presentation Layer
5-- Session Layer
4-- Transport Layer
3-- Network Layer
2-- Data Link Layer
1-- Physical Layer


The TCP/IP Model is more of a realistic and working model representation of how a network works. All of the same information from the OSI Model is within the TCP/IP Model. Some of the layers are condensed and overlap within the TCP/IP Model.

TCP/IP Model
5-- Application Layer
4-- Transport Layer
3-- Network Layer
2-- Data Link Layer
1-- Physical Layer

I will attempt to explain the different layers of both the OSI Model and the TCP/IP Model and compare and contrast the two.

What is Information Security?

It is about securing personal and private information. With information security you have to compromise between security and ease of use. A person can make a security system so secure that no one would use it. For example having a password 30 characters, a mixture of letters, numbers, and special characters. That would be a secure logon, but that also would cause the user to write the password down which is unsecure and anyone that stops by the users desk would be able to grab the password.

The only way to use passwords such as those would be to use a flash drive to copy the password into that logon box. The problem there is that most companies do not allow USB Flash drives within their system. Which is a compromise, so most businesses set-up a 8 character password limit of letters and numbers.

Security is all about accomplishing the business needs, and not as much about rock solid nobody break-in security. Sometimes security professionals forget all about the business needs, and without the business everyone would be without a job.

Next time you design a security system keep in mind how important is the data that your trying to secure, and also what is the business mission and goals are.