Which layer of the OSI model is used to forward packets on the network quizlet?
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Network. Close ports 20, 21, and 80, and open ports 25 and 110. Frame. Layer 2 of the OSI Model (that is, the Data Link Layer) views a unit of data (that is, a protocol data unit) as a frame (or packet). Note that the term "packet" is used fairly generically to refer to data at Layers 2, 3, and 4. At Layer 1 (that is, the Physical Layer), a unit of data is a bit. At Layer 3 (that is, the Network Layer), a unit of data is a datagram (or packet). At Layer 4 (that is, the Transport Layer), a unit of data is a segment (or packet). Students also viewedTerms in this set (14)It connects multiple cable segments (or devices) and forwards frames to the appropriate segment. Switches have multiple ports and can connect multiple segments or devices. The switch forwards frames to the appropriate port. They function similarly to a hub, except instead of sending packets to all ports, switches send packets only to the destination computer's port. When a frame enters a port, the source MAC address is copied from the frame header. Bridges and switches learn addresses by copying the MAC address of the source device and placing it into the MAC address table. The port number that the frame entered is also recorded in the table and associated with the source MAC address. The switch or the bridge cannot record the destination MAC address because it does not know the port that is used to reach the destination device. Bridges and switches operate at Layer 2 and do not use IP addresses (which exist at Layer 3). Send the frame out ports two through eight. Because the switch does not know the port that is used to reach the destination device, it will send the frame out all ports except for the port on which the frame was received. After the switch learns the port that is used to reach the destination device, it will send the frame out only that port. Hub A hub does not create multiple segments on the network. A segment is a portion of the network that has different media, collision domains, or broadcast domains. A hub simply connects devices using the same media type. All devices are members of the same collision and broadcast domains. On a switch, each switch port is in a separate collision domain. With a router or a firewall, each connected network is a different broadcast domain. Switches Network interface cards (NICs), bridges, and switches all operate at the OSI Data Link layer. They use the physical device address (MAC address) to identify packets. Hubs and repeaters operate at the Physical layer--they simply repeat packets without regard to addresses. Routers function at the Network layer--they examine the logical device and network address to perform routing tasks. Network interface card A network interface card and a switch operate at Layer 2 (Data Link) of the OSI model. Layer 2 includes protocols that define the MAC address. The MAC address is burned into the network interface card, and a switch uses the MAC address to make forwarding decisions. A hub or a repeater operate at Layer 1; they regenerate a signal without looking at Layer 2 or Layer 3 information. A router operates at Layer 3, using the IP address to make forwarding decisions. A firewall operates at Layer 3 or higher, using packet or data contents to make filtering decisions. Which layer of OSI model is used to forward packets on the network?Understanding Network Data Delivery: Layers 2 and 3 of the OSI Model. The OSI model has 7 layers, and layer 3, the network layer, is responsible for packet forwarding, including routing through intermediate routers.
What are the responsibilities of Layer 3 in the OSI model quizlet?These devices, then, operate on layer 3 and preform tasks such as packet switching, packet filtering, internetwork communication, and path selection. In the most basic sense, this device is a layer 3 switch, providing connections between virtual LANs (VLAN).
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