OSI Layer


A network is an interconnection of 2 or more devices in order to communicate with each other.

OSI (Open Systems Interconnection)
-To divide complicated process of networking into different layers.
-To allow different vendors networks to interoperate.
-Developing protocols and devices for different layers.
-OSI reference model was introduced by international organization for standardization (ISO).
-It allows various types of network hardware and software to communicate. Continue reading…

Future webhosting


How different will be the kind of future web hosting ? With day by day betterment in technological aspects ,one thing is sure the hardware aspects will be quiet sound that, the processing capability , RAM memory e.t.c may multiples of 10?s of Giga Bytes or more e.t.c
Will that means that there wont be any congestion problems , or problems like sever going down e.t.c, That future is not far away.sure Intels Dual processing system can be considered as a small step towards this. Below are few other concepts towards this.

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About Cacti

Cacti is a PHP/MySQL front end to rrdtool. It handles the storage of all the information required to create and populate rrdtool graphs. Along with being able to maintain Graphs, Data Sources, and RoundRobin Archives in a DataBase, Cacti handles the data gathering also. There is also SNMP support for those used to creating traffic graphs with MRTG.
You can use Cacti to gather any sort of data, or fetch information from SNMP capable hosts.

To manually handle data gathering, you can feed Cacti the Command Line for any external script/command along with any data that the user will need to fill in (IP addresses etc). Cacti will then gather this data in a cron job and populate a MySQL database/the RoundRobin Archives.
Data Sources can also be created, which correspond to actual data on the graph. For instance, if a user wants to graph the ping times to a host, they could create a data source, choosing a script that pings a host and returns its value in milliseconds. After defining options for rrdtool such as how to store the data you will be able to define any additional information that the data input source requires, such as a host to ping in this case. Once a data source is created, it is automatically maintained at 5 minute intervals.
For people who are used to creating traffic graphs in MRTG, this process has become much simpler in Cacti. An SNMP interface allows you to enter SNMP capable hosts and Cacti will display that hosts interfaces, all of which can be graphed with once click from that point.
Once one or more data sources are defined, an rrdtool graph can be created using the data. Cacti allows you to create almost any imaginable rrdtool graph using all of the standard rrdtool graph types and consolidation functions. A color selection area and automatic text padding function also aid in the creation of graphs to make the process easier.
Cacti has a user management system so you can allocate people various levels of access to the program and their own settings.

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KERBEROS The Windows Authentication Protocol

The Internet is an insecure place. Many of the protocols used in the Internet do not provide any security. Tools to sniff passwords off of the network are in common use by malicious hackers. Thus, applications which send an unencrypted password over the network are extremely vulnerable. Worse yet, other client/server applications rely on the client program to be honest about the identity of the user who is using it. Other applications rely on the client to restrict its activities to those which it is allowed to do, with no other enforcement by the server.

Some sites attempt to use firewalls to solve their network security problems. Unfortunately, firewalls assume that the bad guys are on the outside, which is often a very bad assumption. Most of the really damaging incidents of computer crime are carried out by insiders. Firewalls also have a significant disadvantage in that they restrict how your users can use the Internet. (After all, firewalls are simply a less extreme example of the dictum that there is nothing more secure then a computer which is not connected to the network and powered off!) In many places, these restrictions are simply unrealistic and unacceptable. Continue reading…