SRWE_Module_2 FOL.pdf

Welcome  Glad to see everyone again!  Please mute your microphone  Feel free to say hello in the chat  We will begin shortly © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 1 Welcome  Chat rules and etiquette during class  While it is great to connect before class b...

Welcome  Glad to see everyone again!  Please mute your microphone  Feel free to say hello in the chat  We will begin shortly © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 1 Welcome  Chat rules and etiquette during class  While it is great to connect before class begins in the chat space and I encourage that …  During class please only use the chat space for posting questions or trying to answer a question (from myself or classmate) – I very much encourage that as it is a great way to learn Otherwise questions get lost in the chatter and the incessant posting is a distraction while talking/listening © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 2 Module 2: Switching Concepts Switching, Routing, and Wireless Essentials v7.0 (SRWE) Module Objectives Module Title: Switching Concepts Module Objective: Explain how Layer 2 switches forward data. Topic Title Frame Forwarding Topic Objective Explain how frames are forwarded in a switched network. Switching Domains Compare a collision domain to a broadcast domain. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 4 2.1 Frame Forwarding © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 5 Frame Forwarding Switching in Networking Two terms are associated with frames entering or leaving an interface: Ingress – entering the interface Egress – exiting the interface © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 6 Frame Forwarding The Switch MAC Address Table Discuss how a switch makes forwarding decisions. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 7 Frame Forwarding The Switch Learn and Forward Method The switch uses a two-step process: Step 1. Learn – Examines Source Address Adds the source MAC if not in table Resets the time out setting back to 5 minutes if source is in the table Step 2. Forward – Examines Destination Address If the destination MAC is in the MAC address table, then it is forwarded out the specified port. If a destination MAC is not in the table, it is flooded out all interfaces except the one it was received. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 8 Frame Forwarding Store-and-Forward Switching Discuss the characteristics of Store-and-forward switching. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 9 Frame Forwarding Cut-Through Switching Discuss the characteristics of Cut-Through switching. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 10 2.2 Switching Domains © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 11 Switching Domains Collision Domains Describe collisions domains and the benefit of switches. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 12 Switching Domains Broadcast Domains Describe a broadcast domain, how broadcast traffic can propagate, and potential issues. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 13 Switching Domains Alleviate Network Congestion Switches use the MAC address table and full-duplex to eliminate collisions and avoid congestion. Features of the switch that alleviate congestion are as follows: Protocol Function Fast Port Speeds Depending on the model, switches may have up to 100Gbps port speeds. Fast Internal Switching This uses fast internal bus or shared memory to improve performance. Large Frame Buffers This allows for temporary storage while processing large quantities of frames. High Port Density This provides many ports for devices to be connected to LAN with less cost. This also provides for more local traffic with less congestion. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 14 2.3 Module Practice and Quiz © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 15 Module Practice and Quiz What did I learn in this module? Frame Forwarding Ingress is the entry port, egress is the exit port. The switch builds a MAC address table to forward frames on the LAN. The switch can use either the store-and-forward or cut-through method of switch forwarding. Switching Domains Ethernet ports in half-duplex will be a part of a collision domain. Full-duplex will eliminate collision domains. A switch will flood out all interfaces except the ingress port if the frame is a broadcast or if the unicast destination MAC is unknown. Broadcast domains may be broken up by a layer 3 device, like a router. Switches extend broadcast domains, but can eliminate collision domains and relieve congestion. © 2016 Cisco and/or its affiliates. All rights reserved. Cisco Confidential 16