The web is a network application that allows users to obtain documents from. It can also perform basic routing functions between virtual lans. Introduction there is an increasing trend toward migrating applica. Note that network layer addresses can also be referred to as logical addresses. One network layer protocol more diversity at other layers no presentation or session layers standards driven by implementations application web,ftp,smtp network ip transport tcp,udp datalink ethernet,802. In an ip layer 3 network, the ip portion of the datagram has to be read.
These comparisons are based on the original seven layer protocol model as defined in iso 7498, rather than refinements in the internal organization of the network layer. It is the protocol layer that enables the transfer of data between adjacent network nodes in a network segment, such as a local or wide area network. Lecture 06 network layer fundamentals lan, wan layer i. The network layer is interested in getting messages to the corresponding network layer module on an adjacent machine. The ubiquity of carrierprovided layer 2 wan networks makes it a required consideration for an organization building a wan. It is a network layer that determines the best available path in the network for communication.
The first two layers of the open systems interconnection osi model deal with the physical structure of the network and the means by which network devices can send information from one device on a network to another. Network protocols acronyms and abbreviations list of network protocols with abbreviations order by index. Data link layer protocols the data link layer provides service to the network layer above it. Those specific to each layer 3 protocol each link that uses ppp has one lcp link control protocol per link and one cp control protocol for each layer 3 protocol defined on the link. Carrier ethernetenabled applications the applications enabled by a carrier ethernet network infrastructure include ethernet layer 2 networking and ethernet access to ip layer 3 services. A protocol suite is a set of different network protocols that cooperate to exchange information and enable internet connectivity across various layers.
Two of the most common network layer protocols are. Layer 2 protocols 1 29 layer 2 protocols 1 ethernet broadcast network equal access csmacd carrier sense multiple access collision detection token ring one node transmits, all receive broadcast each node transmits in turn failure in a node affects the entire ring 029 ethernet we use almost. N2n is an encrypted layer two private network using a p2p protocol. Ip version 4 ipv4 and ip version 6 ipv6 are covered in nauseating detail in other guides. Those needed regardless of the layer 3 protocol sent across the link 2.
Ahmed elshafee, acu fall2016, computer networks ii osi layer 2 of wans 9. Layer 2 network design network startup resource center. When a destination exists on another network, the communication must be directed by a router to the other network2. Layer 2, also known as the data link layer, is the second level in the seven layer osi reference model for network protocol design. For now, network managers should plan on mstp for at least the next five years. The layer 3 switch functions at the network layer and performs the multiport, virtual lan, data pipelining functions of a standard layer 2 switch. Protocol analyzer ensures proper decoding along with call and session analysis. In layer 2, communication can only occur among devices on the same network segment. Layer 2 is equivalent to the link layer the lowest layer in the tcpip network model. Tcpip combines the osi data link and physical layers into one layer. Knowing your layer 2 and layer 3 protocols biztech magazine. Tcp state can be easy to guess enables spoofing and session hijacking 3.
The key components of the juniper networks mx series 5g universal routing platforms are. Possible services that can be offered by a link layer protocol include. Datalink layer protocols that are reliant on a specific physical layer may be limited to the transmission medium involved, but, in some cases e. Internet protocol ip 304 internetworking technology overview, june 1999 optionsallows ip to support various options, such as security. Layer 2 network design guidelines always connect hierarchically if there are multiple switches in a building, use an aggregation switch locate the aggregation switch close to the building entry point e. Data link layer 2 the data link layer takes the packet from the network layer and breaks it into frames. Multiple choice questions of computer networking 31. An application layer protocol is only one piece albeit, a big piece of a network application.
The ohio state university raj jain 2 9 layering protocols of a layer perform a similar set of functions all alternatives for a row have the same interfaces choice of protocols at a layer is independent of those of at other layers. Network layer protocols 2015 jens andersson etsf05etsf10 internet protocols. The increased availability and popularity of highspeed carrier ethernet services. The remote network layer peer should receive the identical message generated by the sender e. Layer 3 network pim source specific mode communication flow. A datalink protocol specifies the structure of the. Layer 2 is where data packets are encoded and decoded into actual bits. Application layer protocols it is important to distinguish between network applications and application layer protocols. While layer 2 protocols such as stp operate within a lan environment, routing between subnets requires layer 3 dynamic routing to minimize management costs and maximize network uptime. For protocol testing, you need protocol analyzer and simulator. Layer 3 the network layer layer 3, the network layer of the osi model, provides an endtoend logical addressing system so that a packet of data can be routed across several layer 2 networks ethernet,token ring, frame relay, etc. Vmware virtual san layer 2 and layer 3 network topologies deployments.
The actual protocols encompassed in the link layer are numerous, and the implementation details can be found in various documents throughout the internet and in trade texts. In order to prevent layer 2 loops on a switched network, switches use the spanning tree protocol to determine which ports can forward frames at a particular time. The header in this layer provides the source and destination mac addresses. When to encrypt at layer 2 or layer 3 network computing. Layer 2 data link layer encryption is a highperformance security option that offers some advantages over layer 3 networking layer encryption in some scenarios, particularly in unified communications environments that require lowlatency, highvolume data transmission. Mx series router architecture techlibrary juniper networks. With source specific multicast, shortestpath trees are built and are rooted in just one source, offering a more secure and scalable model for a limited amount of applications mostly broadcasting of. Network layer and ip protocol cse 32, winter 2010 instructor. Ip addressing as with any other network layer protocol, the. Network packets pass by untrusted hosts eavesdropping, packet sniffing especially easy when attacker controls a machine close to victim 2.
Metro ethernet forum layer 2 control protocol handling. Routing protocols general terms algorithms, design, performance, management, reliability keywords data center network fabric, layer 2 routing in data centers 1. Within the discussion of content networking, we will. By far, the most popular set of protocols for the physical and data link layers is ethernet. Layer 2 refers to the second layer of the open systems interconnection osi model, which is the data link layer. The link layer corresponds to the osi data link layer and may include similar functions as the physical layer, as well as some protocols of the osis network layer. Introduction to networking protocols and architecture. A layer 3 switch is a highperformance device for network routing. Osi model the datalink layer while the network layer is concerned with transporting. While a protocol that affects the configuration or operation of a layer 2 network can use any type of frame with ordinary unicast or multicast addresses, the protocols that are considered layer 2 control protocols with the reserved addresses above can take advantage of special.
The spanning tree protocol is an algorithm which was developed by radia perlman and standardized as the ieee 802. Layer2 is the network layer used to transfer data between adjacent network nodes in a wide area network or between nodes on. It is the data link layer that will convert the data into binary digits such as 1 and 0 and then prepare them for the physical layer. Internet protocol ip novells internetwork packet exchange ipx. A router works with ip addresses at layer 3 of the model. Vmware virtual san layer 2 and layer 3 network topologies. This requires stripping off the datalink layer frame information. Data link layer, layer 2 in the tcpipbased layered network, layer 2 is the data link layer. Carrier ethernet transport technologies, leveraging a heterogeneous set of transport network technologies. Layer 2 wan services provide highperformance, costeffective, and reliable services within metropolitan areas and, in some cases, for broader geographic areas. Protocol encapsulation chart a pdf file illustrating the relationship between common protocols and the osi reference model.
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