April Fools Shows
On September the 10th, 2012 an anonymous malicious hacker released 10,000 pin codes onto the site paste bin dot com. How the attacker gained access to the codes is not known, but it is thought that it may be linked to a breach that occurred at the end of March 2012 to the Credit card processor Global Payments. That attack exposed 1.5 million consumers financial data. These codes have been confirmed by security experts to be legitimate and in wide spread use even today. Despite this exposure been "common knowledge" among the security community, major banks and credit card companies have yet to issue any statement on the breach.
Tired of waiting for action by big business, we bring you a list of the codes so you can check for yourself if your data is compromised.
In today's show we continue our look at The OSI model for network communications, with examples of Layer 3 been given with particular focus on Geography diverse Host addressing.
From Wikipedia: https://en.wikipedia.org/wiki/OSI_layer_3
In the seven-layer OSI model of computer networking, the network layer is layer 3. The network layer is responsible for packet forwarding including routing through intermediate routers, whereas the data link layer is responsible for media access control, flow control and error checking.
The network layer provides the functional and procedural means of transferring variable-length data sequences from a source to a destination host via one or more networks, while maintaining the quality of service functions.
Functions of the network layer include:
- Connection model: connectionless communication
- For example, IP is connectionless, in that a datagram can travel from a sender to a recipient without the recipient having to send an acknowledgement. Connection-oriented protocols exist at other, higher layers of the OSI model.
- Host addressing
- Every host in the network must have a unique address that determines where it is. This address is normally assigned from a hierarchical system. For example, you can be "Fred Murphy" to people in your house, "Fred Murphy, 1 Main Street" to Dubliners, or "Fred Murphy, 1 Main Street, Dublin" to people in Ireland, or "Fred Murphy, 1 Main Street, Dublin, Ireland" to people anywhere in the world. On the Internet, addresses are known as Internet Protocol (IP) addresses.
- Message forwarding
- Since many networks are partitioned into subnetworks and connect to other networks for wide-area communications, networks use specialized hosts, called gateways or routers, to forward packets between networks. This is also of interest to mobile applications, where a user may move from one location to another, and it must be arranged that his messages follow him. Version 4 of the Internet Protocol (IPv4) was not designed with this feature in mind, although mobility extensions exist. IPv6 has a better designed solution.
Within the service layering semantics of the OSI network architecture, the network layer responds to service requests from the transport layer and issues service requests to the data link layer.
In this the first in a series exploring The Open Systems Interconnection (OSI) model (ISO/IEC 7498-1)
From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/OSI_model
The Open Systems Interconnection (OSI) model (ISO/IEC 7498-1) is a product of the Open Systems Interconnection effort at the International Organization for Standardization. It is a prescription of characterizing and standardizing the functions of a communications system in terms of abstraction layers. Similar communication functions are grouped into logical layers. A layer serves the layer above it and is served by the layer below it.
For example, a layer that provides error-free communications across a network provides the path needed by applications above it, while it calls the next lower layer to send and receive packets that make up the contents of that path. Two instances at one layer are connected by a horizontal connection on that layer.
In today's show Ken starts off with a practical example of Layer One, the The Physical Layer, https://en.wikipedia.org/wiki/Physical_layer. Although we are limited to audio for the purposes of the show, the same techniques could and are used across the light spectrum.