Unformatted text preview: is the Media
Access Control (MAC) address, which is
a 6-byte address written in hexadecimal
The first 3 bytes of the address indicate
the vendor or manufacturer of the
physical network interface.
The last 3 bytes represent a unique
number assigned to that interface by the Data Link Layer … cont.
Among the protocols at the Data Link
layer (layer 2) of the OSI model, the two
you should be familiar with are Address
Resolution Protocol (ARP) and Reverse
Address Resolution Protocol (RARP).
ARP is used to resolve IP addresses
into MAC addresses.
Traffic on a network segment (e.g.,
cables across a hub) is directed from its
source system to its destination system
using MAC addresses. Data Link Layer … cont.
Contains two sub-layers: the Logical
Link Control (LLC) sub-layer and the
Network hardware devices that function
at layer 2, the Data Link layer, are
switches and bridges.
These devices support MAC-based
Switches receive a frame on one port
and send it out another port based on
the destination MAC address. Network Layer
Responsible for adding routing and
addressing information to the data.
The Network layer accepts the segment
from the Transport layer and adds
information to it to create a packet.
The packet includes the source and
destination IP addresses. Lecture-3 19 Network Layer …cont.
Protocols working at this layer:
Internet Control Message Protocol
Routing Information Protocol (RIP)
Open Shortest Path First (OSPF)
Border Gateway Protocol (BGP)
Internet Group Management Protocol
Internet Protocol (IP)
Internet Protocol Security (IPSec)
Lecture-3 20 Network Layer …cont.
Responsible for providing routing or
Not responsible for verifying guaranteed
delivery (that is the responsibility of the
Manages error detection and node data
traffic (i.e., traffic control).
Routers are among the network
hardware devices that function at layer...
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This note was uploaded on 01/21/2014 for the course IT 205 taught by Professor Kurts during the Winter '08 term at University of Phoenix.
- Winter '08