layer 3 , network layer .
TCP/IP because the osi model has seven layer but in tcp/ip only four layers and most important is that the tcp/ip model is reduce the function of osi model.
Router is a Layer 3 (Network Layer)device that checks packet's IP Address at input interface & routes them to interface connected to destination network if available.
ARP (Address Resolution Protocol) is used resolve known IP Address to the Machines MAC Address (Layer 2 - OSI Layer). Whereas RARP is used to resolve IP Adresses from know layer 2 address.ARP is still used while RARP has been replaced with DHCP.
Network Interface Layer
ARP stands for Address resolution Protocol.......it is the method for finding a host's link layer (hardware) address when only its Internet Layer (IP) or some other Network Layer address is knowns the method for finding a host's link layer (hardware) address when only its Internet Layer (IP) or some other Network Layer address is known. Source: http://en.wikipedia.org/wiki/Address_Resolution_Protocol
DHCP runs at the application layer of the OSI model.
Layer 3 - network addressing.
Layer 3 i.e, network layer of the OSI model is used to IP addressing.
IP addresses are used primarily by layer 3 (network layer) of the OSI model for routine purposes.
The network layer uses IP addresses to determine whether or not to route a packet from one network to another. Since an IP address has two parts, the network id and the host/client id, this makes it a natural fit (IP addressing) for the network layer.
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IP operates at layer 3, this is the NETWORK LAYER in the OSI Model. Network+ Guide to Networks Fifth Edition Ch02, pg56, Figure 2-7
Layer 3 of the OSI model. An ICMP header follows the IP header of the IP packet.
Layer 3 - network layer.
It works the same on all Layer 1 media. IP encapsulates OSI Layer 4 data. IP can carry voice, video, and other types of data, but "media independent" refers to the OSI Layer 1 medium that carries the data across the networks. IP, or any other communication, can occur without a physical (OSI Layer 1) medium
The Application layer The Presentation layer The Session layer
TCP operates at Layer 4 which is Transport of the OSI Model!