Redhat network

Millions of pieces of malware and thousands of malicious hacker gangs roam today's online world preying on easy dupes. Reusing the same tactics that have worked for years, if not decades, they do nothing new or interesting in exploiting our laziness, lapses in judgment, or plain idiocy.

But each year antimalware researchers come across a few techniques that raise eyebrows. Used by malware or hackers, these inspired techniques stretch the boundaries of malicious hacking. Think of them as innovations in deviance. Like anything innovative, many are a measure of simplicity.

***Network Classes:** Very important Topic

The concept of network classes is a little obsolete as subnets are now used to define smaller networks using CIDR (Classless Inter-Domain Routing) as detailed above. These subnets may be part of a class A, B, C, etc network. For historical reference the network classes are defined as follows:

=> Class A: Defined by the first 8 bits with a range of 0 - 127.
First number (8 bits) is defined by Internic i.e. 77. # # #. # # #. # # #
One class A network can define 16,777,214 hosts.
Range: 0.0.0.0 - 127.255.255.255
=> Class B: Defined by the first 8 bits with a range from
128 -191
First two numbers (16 bits) are defined by Internic i.e. 182.56. # # #. # # #
One class B network can define 65,534 hosts.
Range: 128.0.0.0 - 191.255.255.255
=> Class C: Defined by the first 8 bits with a range from
192 - 223
First three numbers (24 bits) are defined by Internic i.e. 220.56.222. # # #
One class B network can define 254 hosts.
Range: 192.0.0.0 - 223.255.255.255
=> Class D: Defined by the first 8 bits with a range from
224 - 239
This is reserved for multicast networks (RFC988)
Range: 224.0.0.0 - 239.255.255.255
=> Class E: Defined by the first 8 bits with a range from
240 - 255
This is reserved for experimental use.
Range: 240.0.0.0 - 247.255.255.255

***Market and future of Linux and Unix***

According to International Data Corp. (IDC).Linux has grown faster than any other server OS over the past few years. Linux user base is estimated to be about more than 25 million machines, compared to 5.5 million for combined UNIX installations.
Linux is gaining popularity because of its application in embedded technologies, free and easily availability. To compete with Linux, vendors such as HP, IBM, Sun are making customized UNIX with graphical user interface and user friendly interface which is also compatible with Linux. The main UNIX vendors--IBM, Sun, and Hewlett-Packard are already putting Linux interoperability features into future releases of AIX, Solaris, and HP-UX.