Layer 3

What Does Layer 3 Mean?

Layer 3 refers to the third layer of the Open Systems Interconnection (OSI) Model, which is the network layer.

Layer 3 is responsible for all packet forwarding between intermediate routers, as opposed to Layer 2 (the data link layer), which is responsible for media access control and flow control, as well as error checking of Layer 1 processes.

Techopedia Explains Layer 3

Layer 3 provides the network’s routing and switching technologies that create logical paths known as virtual circuits (VC), which are used for the transmission of data between network nodes. The main functions of Layer 3 include routing and forwarding, as well as internetworking, addressing, packet sequencing, congestion control and further error handling.

The protocols used in Layer 3 include:

• Internet Protocols IPv4/v6
• Internet Control Message Protocol (ICMP)
• Distance Vector Multicast Routing Protocol (DVMRP)
• Internet Group Management Protocol (IGMP)
• Address Resolution Protocol (ARP)
• Internet Protocol Security (IPsec)
• Routing Information Protocol (RIP)