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NETWORK LAYERS andADDRESSES

Prepared By:

Khurram Shahzad

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Logical Address vs Physical Address

PHYSICAL ADDRESS

A Physical address is a 48-bit flat address burned into the ROM of the NIC card which is a Layer1device of the OSI model. This iis divided into 24-bit vendor code and 24-bit serial address. This isunique for each system and cannot be changed.

LOGICAL ADDRESSA Logical address is a 32- bit address assigned to each system in a network. This worksin Layer-3 of OSI Model. This would be generally the IP address.

Simply we can say that Physical address is MAC address (Media AccessControl) which is inbuilt and Logical Address is the IP which is given manually.

Because a MAC address is assigned (by the FCC) to a company to use for arange of products.For example:01:23:45:00:00:00 - 01:23:45:FF:FF:FF

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Public IP Address /Network Address

Public IP Address / Netwrok Address

Every device connected to the public Internet is assigned a unique numberknown as an Internet Protocol (IP) address. IP addresses consist of fournumbers separated by periods (also called a 'dotted-quad') and looksomething like 127.0.0.1.

Since these numbers are usually assigned to internet service providers withinregion-based blocks, an IP address can often be used to identify the region orcountry from which a computer is connecting to the Internet. An IP addresscan sometimes be used to show the user's general location.

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LAN Address or Private IP Address

In the Internetaddressing architecture, a private networkis a networkthat uses privateIP addressspace. These addresses are commonly used for home, office, and enterpriselocal area networks(LANs), when globally routable addresses are not mandatory, or arenot available for the intended network applications.

These addresses are characterized as private because they are not globally delegated,meaning they are not allocated to any specific organization, and IP packets addressed bythem cannot be transmitted onto the public Internet. Anyone may use these addresseswithout approval from a regional Internet registry(RIR). If such a private network needsto connect to the Internet, it must use either a network address translator(NAT) gateway,or a proxy server.

Private IP Address /Network Address

http://en.wikipedia.org/wiki/Internethttp://en.wikipedia.org/wiki/Computer_networkhttp://en.wikipedia.org/wiki/IP_addresshttp://en.wikipedia.org/wiki/Local_area_networkhttp://en.wikipedia.org/wiki/Regional_Internet_registryhttp://en.wikipedia.org/wiki/Network_address_translatorhttp://en.wikipedia.org/wiki/Proxy_serverhttp://en.wikipedia.org/wiki/Proxy_serverhttp://en.wikipedia.org/wiki/Network_address_translatorhttp://en.wikipedia.org/wiki/Regional_Internet_registryhttp://en.wikipedia.org/wiki/Local_area_networkhttp://en.wikipedia.org/wiki/IP_addresshttp://en.wikipedia.org/wiki/Computer_networkhttp://en.wikipedia.org/wiki/Internet

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ISO/OSI LAYERS

Physical Layer 1 Data flows physically

Data Link Layer 2 Uses MAC Addresses

Network Layer 3 Uses IP/Network Addresses

Transport Layer 4 Reliable Delivery and ack.

Session Layer 5 Creates Session

Presentation Layer 6 O.S works to convert data.

Application Layer 7 Browser works here.

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Layer 1 Devices

Cables

Connectors

Hub

Csu/Dsu (Channel Service Unit/Data Service Unit)

Modem

Repeaters

http://en.wikipedia.org/wiki/Channel_service_unithttp://en.wikipedia.org/wiki/Data_service_unithttp://en.wikipedia.org/wiki/Data_service_unithttp://en.wikipedia.org/wiki/Channel_service_unit

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Layer 2 Devices

Switch Utilizes MAC/Physical Address

Bridges

Layer 3 Devices

Routers Utilizes IP/Network Address

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THANK YOU!