Table of Contents
What device operates at OSI Layer 2?
A Layer 2 switch is a device that operates according to the Layer 2 data communications protocol. A Layer 2 device decides how to forward data based on the MAC address. Ethernet hubs and network switches work at the data link layer, with a switch delivering greater performance than a hub.
On which layers of the OSI model does the Internet work?
The Internet Layer of the TCP/IP model aligns with the Layer 3 (Network) layer of the OSI model. This is where IP addresses and routing live. When data is transmitted from a node on one LAN to a node on a different LAN, the Internet Layer is used.
Which layer of OSI model has 2 protocols?
Data Link
What is a Protocol?
| OSI Layer | Name | Common Protocols |
|---|---|---|
| 4 | Transport | TCP | SPX |
| 3 | Network | IP | IPX |
| 2 | Data Link | Ethernet |
| 1 | Physical |
Is a router a layer 2 device?
The most common Layer 3 device used in a network is the router. A router is able to look into the Layer 3 portion of traffic passing through it (the source and destination IP addresses) to decide how it should pass that traffic along.
Is VLAN a Layer 3?
VLANs are data link layer (OSI layer 2) constructs, analogous to Internet Protocol (IP) subnets, which are network layer (OSI layer 3) constructs. In an environment employing VLANs, a one-to-one relationship often exists between VLANs and IP subnets, although it is possible to have multiple subnets on one VLAN.
Is ARP a Layer 3?
ARP works between Layers 2 and 3 of the Open Systems Interconnection model (OSI model). The MAC address exists on Layer 2 of the OSI model, the data link layer. The IP address exists on Layer 3, the network layer.
What layer is DNS?
Layer 7
We know what DNS is, but what about the DNS layer? At a high level, the DNS protocol operates (using OSI model terminology) at the application level, also known as Layer 7. This layer is shared by HTTP, POP3, SMTP, and a host of other protocols used to communicate across an IP network.
What layer is a router?
network layer
Layer 3, the network layer, is most commonly known as the layer where routing takes place. A router’s main job is to get packets from one network to another. Layer 3 protocols and technologies allow for network-to-network communications.
Is VLAN a Layer 2?
What are the 3 types of VLANs?
Types of VLAN
- Management VLAN.
- Data VLAN.
- Voice VLAN.
- Default VLAN.
- Native VLAN.
What do you need to know about Wan operations?
This topic introduces common WAN terminology and devices and differentiates between circuit-switch and packet-switch networks. As shown in Figure 2-6, WAN operations focus primarily on the physical layer (OSI Layer 1) and the data link layer (OSI Layer 2).
What are the different types of Wan standards?
WAN access standards typically describe both physical layer delivery methods and data link layer requirements, including physical addressing, flow control, and encapsulation. WAN access standards are defined and managed by a number of recognized authorities, including the
What’s the difference between a LAN and a WAN?
Most WAN links are point to point. For this reason, the address field in the Layer 2 frame is usually not used. One primary difference between a WAN and a LAN is that an organization must subscribe to an outside WAN service provider and use the WAN carrier network services to interconnect its sites and users.
What kind of protocols are used in Layer 2?
Layer 2 protocols define how data is encapsulated for transmission toward a remote location, and the mechanisms for transferring the resulting frames. A variety of different technologies are used, such as the Point-to-Point Protocol (PPP), Frame Relay, and Asynchronous Transfer Mode (ATM).