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Temat artykułu: Data Link and Network Addressing
Tekst napisał pitt2k dnia 08-01-2004
MAC Addresses
Uniquely identifies devices on the same medium. Addresses are 48 bits in length and are expressed as 12 hexadecimal digits. The first 6 digits specify the manufacturer and the remaining 6 are unique to the host. An example would be 00-00-13-35-FD-AB. No two MAC addresses are the same in the world.
Ultimately all communication is made to the MAC address of the card. Protocols such as ARP and RARP are used to determine the IP to MAC address relationship. MAC addresses are copied to RAM when a network card is initialized.
Data Link Addresses
Addresses that operate at the data link layer. A MAC address is a data link layer address and these are built in by the manufacturer and cannot usually be changed. They can be virtualized for Adapter Fault Tolerance or HSRP. Switches and Bridges operate at the Data Link layer and use Data Link addresses to switch/bridge.
Network Addresses
Addresses that operate at the Network Layer. These are IP addresses or IPX addresses that are used by Routers to route packets. Network addresses are made up of two parts, the Network number and the Host ID. IP addresses are 32 bit dotted decimal numbers. IPX addresses are 80 bit dotted hexadecimal numbers. Network addresses are host specific and one must be bound to each interface for every protocol loaded on the machine. There is no fixed relationship between the host and the Network Address.
For example, a router with three interfaces, each running IPX, TCP/IP, and AppleTalk, must have three network layer addresses for each interface. The router therefore has nine network layer addresses.
REMEMBER THIS !!!
MAC addresses uniquely identify devices on the same medium. MAC addresses consist of 48 bit hexadecimal numbers. Know what a valid MAC address looks like. IP addresses are 32 bit dotted decimal numbers. MAC addresses are copied into RAM when the network card initializes. A Network address consists of 2 parts 1) Network number and 2) Host number. The hardware address is used to transmit a frame from one interface to another.
Why a Layered Model?
Standardizing hardware and software to follow the 7 layers of the OSI Model has several major benefits:
Opracowanie na podstawie materiałów TroyTech (www.troytech.com).
Temat artykułu: Data Link and Network Addressing
Tekst napisał pitt2k dnia 08-01-2004
MAC Addresses
Uniquely identifies devices on the same medium. Addresses are 48 bits in length and are expressed as 12 hexadecimal digits. The first 6 digits specify the manufacturer and the remaining 6 are unique to the host. An example would be 00-00-13-35-FD-AB. No two MAC addresses are the same in the world.
Ultimately all communication is made to the MAC address of the card. Protocols such as ARP and RARP are used to determine the IP to MAC address relationship. MAC addresses are copied to RAM when a network card is initialized.
Data Link Addresses
Addresses that operate at the data link layer. A MAC address is a data link layer address and these are built in by the manufacturer and cannot usually be changed. They can be virtualized for Adapter Fault Tolerance or HSRP. Switches and Bridges operate at the Data Link layer and use Data Link addresses to switch/bridge.
Network Addresses
Addresses that operate at the Network Layer. These are IP addresses or IPX addresses that are used by Routers to route packets. Network addresses are made up of two parts, the Network number and the Host ID. IP addresses are 32 bit dotted decimal numbers. IPX addresses are 80 bit dotted hexadecimal numbers. Network addresses are host specific and one must be bound to each interface for every protocol loaded on the machine. There is no fixed relationship between the host and the Network Address.
For example, a router with three interfaces, each running IPX, TCP/IP, and AppleTalk, must have three network layer addresses for each interface. The router therefore has nine network layer addresses.
REMEMBER THIS !!!
MAC addresses uniquely identify devices on the same medium. MAC addresses consist of 48 bit hexadecimal numbers. Know what a valid MAC address looks like. IP addresses are 32 bit dotted decimal numbers. MAC addresses are copied into RAM when the network card initializes. A Network address consists of 2 parts 1) Network number and 2) Host number. The hardware address is used to transmit a frame from one interface to another.
Why a Layered Model?
Standardizing hardware and software to follow the 7 layers of the OSI Model has several major benefits:
- It reduces complexity
- Allows for standardization of interfaces
- Facilitates modular engineering
- Ensures interoperability
- Accelerates evolution
- Simplifies teaching and learning
Opracowanie na podstawie materiałów TroyTech (www.troytech.com).