Showing posts with label cisco networking. Show all posts
Showing posts with label cisco networking. Show all posts

5.12.12

TCP/IP Protocol Suite explained briefly

TCP/IP is based on a four-layer reference model. All protocols that belong to the TCP/IP protocol suite are located in the top three layers of this model. As shown in the following diagram, each layer of the TCP/IP model corresponds to one or more layers of the seven-layer Open Systems Interconnection (OSI) reference model proposed by the International Organization for Standardization (ISO). Diagram The types of services performed...

5.9.11

Internet Protocol (IP) Addresses

Because TCP/IP networks are interconnected across the world, each computer on the Internet must have a unique address (called an IP address) to make sure that transmitted data reaches the correct destination. Blocks of addresses are assigned to organizations by the internet Assigned Numbers Authority (IANA). Individual users and small organizations may obtain their addresses either from the IANA or from an Internet service provider...

Basic Router Concepts

What is a Router? A router is a device that forwards traffic between networks based on network layer information in the data and on routing tables aintained by the router. In these routing tables, a router builds up a logical picture of the overall network by gathering and exchanging information with other routers in the network. Using this information, the router chooses the best path for forwarding network traffic. Routers vary in performance and scale, number of routing protocols supported, and types ofphysical WAN...

8.12.10

Security in Network

What is IT-Security? IT-Security is not a product, it's a process. Don't think to buy a firewall which solves all your security problems! You always have to ensure good configuration and updates - this should be an integrated process. But you never will reach 100% of security, it's like a bank safe: you can make it difficult to crack, but there will always be somebody, who is able to break it with a lot of resources! Here are the most important components of IT-Security: Authenticity Authenticity is about the identity...

20.4.10

IPv6 and its difference from IPv4

Internet Protocol version 6 (IPv6) is the next-generation Internet Protocol version designated as the successor to IPv4, the first implementation used in the Internet that is still in dominant use currently. It is an Internet Layer protocol for packet-switched internetworks. The main driving force for the redesign of Internet Protocol is the foreseeable IPv4 address exhaustion. IPv6 was defined in December 1998 by the Internet Engineering Task Force (IETF) with the publication...

How Network Address Translation (NAT) works

Introduction If you are reading this, you are most likely connected to the Internet and there's a very good chance that you are using Network Address Translation (NAT) right now! The Internet has grown larger than anyone ever imagined it could be. Although the exact size is unknown, the current estimate is that there are about 100 million hosts and over 350 million users actively on the Internet. That is more than the entire population...

21.3.10

Characteristics of a Network

Many characteristics are commonly used to describe and compare various network designs. When you are determining how to build a network, each of these characteristics must be considered along with the applications that will be running on the network. The key to building the best network is to achieve a balance of these characteristics. Networks can be described and compared according to network performance and structure, as follows: ■ Speed: Speed is a measure of how fast data is transmitted over the network. A more precise term would be data...

Network User Applications

The key to utilizing multiple resources on a data network is having applications that are aware of these communication mechanisms. Although many applications are available for users in a network environment, some applications are common to nearly all users. The most common network user applications include the following: ■ E-mail: E-mail is a valuable application for most network users. Users can communicate information (messages and files) electronically in a timely manner, to not only other users in the same network but also other users...

What is a Network, I mean computer Network?

The first task in understanding how to build a computer network is defining what a network is and understanding how it is used to help a business meet its objectives. A network is a connected collection of devices and end systems, such as computers and servers, that can communicate with each other. Networks carry data in many types of environments, including homes, small businesses, and large enterprises. In a large enterprise, a number of locations might need to communicate with each other, and you can describe those locations as follows: ■...

Introduction to networking

From Wikipedia, the free encyclopedia Jump to: navigation, search CCNA is the acronym for the Cisco Certified Network Associate certification from Cisco. In speech and in writing, this certification is properly referred to by the initials CCNA rather than the full name. CCNA certification is a second-level Cisco Career certification . CCNA certification validates the ability to install, configure, operate, and troubleshoot medium-size routed and switched networks, including implementation and verification of connections to remote sites...