Switching and Routing Concepts

• This study guide covers switching and routing concepts, including LAN technologies, VLANs, and routing protocols.
• It includes lab demonstrations and practical applications for configuring and troubleshooting network devices.

Philosophy of Training

• The 81st Training Group emphasizes individual development, recognizing the worth and potential of each student.
• It supports professional development and innovation in teaching methods.

Switching and Routing Overview

• It serves as course material for switching and routing.
• Covers LAN technology and switching, VLANs, routing fundamentals, IP addressing, subnetting, network diagrams, and troubleshooting

Unit 1: LAN Technologies

• Introduces LAN technology concentrating on switching concepts.
• Includes labs to support the understanding of basic facts by providing practical applications
• Objectives include identifying relationships of switching concepts, protocols, and standards.
• Configuration and application of Security Technical Implementation Guides (STIGs) to switching devices.

Network Switch

• A switch is hardware based, using Application Specific Integrated Circuits (ASICs) for filtering decisions.
• Switches connect LAN components like computers, printers, and other switches.
• Switches use the MAC address to regulate traffic flow, improving security and network efficiency.
• Layer 2 Ethernet switches work at the Data-Link Layer of the OSI model, while multilayer switches operate across multiple layers.
• Collision domains are created by each port on a switch because the port bandwidth is not shared with other devices.

Switch Performance

• Hardware-based bridging (MAC): uses ASICs to learn and form internal connections for traffic management.
• Wire Speed: configurable to the media speed (e.g., 100 Mbps for Ethernet).
• Low Latency: processes and updates quickly.
• Low Cost: Inexpensive as relates to the number of ports.
• Broadcast Control: Segments networks if used with VLANs, but without VLANs, broadcasts reaches a Layer 3 device.

External Components

• Console Port: Enables direct, local configuration using terminal emulation software.
• Network Interfaces (Switch Ports): Connect end devices and can be used to test connectivity (Ping).

Internal Components

• Flash Memory: Stores the OS
• Read-Only Memory (ROM): Burns diagnostic and boot up routines
• RAM: Used by the switch for all its operations, and sotres the running configuration of the switch.
• NVRAM: Keeps the startup configuration and other info for long-term storage.
• Switches use MAC addresses to forward/filter Layer 2 Frames.

Layer 2 Protocols and Standards

• Point-to-Point Protocol (PPP): Establishes direct communication between two network devices.
• Spanning Tree Protocol (STP): Defined by IEEE 802.1D, prevents loops in a network.
• IEEE 802.1D: Ethernet MAC bridges standard, including bridging and STP.
• Unidirectional Link Detection (UDLD) and Loopguard: UDLD shuts down ports with hearing issues; Loopguard puts ports in an inconsistent state.
• Link Layer Discovery Protocol (LLDP): Vendor-neutral for network management, advertises data and Layer 2 configurations to adjacent nodes; stores MAC address, VLAN, etc.
• cisco Discovery Protocol (CDP): Cisco proprietary, shares information between directly connected Cisco devices.
• IEEE 802.1q: Encapsulates a VLAN frame within the standard frame header.
• ISL: Tags the frame, adding a new header and trailer; works only with Cisco devices

Layer 2 Standard Functionality

• Essential Functions: Ethernet switches segment a network into multiple collision domains by forwarding frames.
• Address Learning: Layer 2 switches learn MAC addresses of connected devices, storing them in a MAC address table (Content Addressable Memory).
• Forward/Filter Decision: Switches forward frames only to the intended interface using the MAC address table, a processes called frame filtering.
• Loop Avoidance: Prevents network wide issues by stopping transmission to avoid broadcast storms, multiple frame copies, and multiple loops

Switching Methods

• Store-and-Forward: Checks entire frame for errors before forwarding; discards bad frames with CRC.
• Cut-Through: Copies only the destination MAC address into memory, forwards bad frames.
• Fragment-Free: Hybrid of Store-and-Forward and Cut-Through that stores the first 64 bytes before forwarding.

Unit 2: VLAN Fundamentals

• Focuses on Virtual Local Area Networks (VLANs).
• Topics include VLAN functionality, benefits, switchport membership, and trunking.
• Includes labs for VLAN configuration and logical security, and applications for Security Technical Implementation Guides (STIGs).

VLAN Fundamentals

• Keep network traffic local by segmenting the network. VLANs limit broadcasts and require Layer 3 routing for inter-VLAN communication.

VLAN Benefits

• Increased Security: Security is improved as only devices in the same VLAN receive the frame.
• Flexibility and Scalability: Flexibility is added as you limit or add devices to broadcast domains.
• No Geographical Barrier: Physical location does not stop the creation of workgroups

Creating VLANs

• VLANs can span multiple switches (Access Switches (ASWs) and Distribution Switches (DSWs)).
• Cisco switches have default VLAN 1 already created.
• VLANs are identified by number (e.g., VLAN 10), have a name (e.g., "Sales"), and then assigned a number.

VLAN Switchport Memberships

• Initially, all switch ports are assigned to default VLAN 1.
• VLAN membership indicates which VLANs are assigned to a certain physical port for traffic filtering.
• Ports not in use should be shut down and assigned to an inactive VLAN.

VLAN Trunking

• Trunk carries more than one VLAN.
• Frame Tagging: Assigns a user-defined trunking ID to each frame with ID matching VLAN of the traffic..
• Tagged Ports: Trunks.
• Untagged Ports: Access ports.
• Cisco proprietary standard for trunks (deprecated). Inter-Switch Link (ISL).
• IEEE 802.1q: Defined open standard for trunks and encapsulates a VLAN frame using a space in the standard frame header.

Management VLANs

• Best practices should be implemented.
• A process for telnet, Simple Network Management Protocol (SNMP), and syslog is maintained.
• Prune unnecessary ports from accruing access, as well as separate in-band management, device protocol, and data traffic.

Unit 3: Routing Fundamentals

• Focuses on routing fundamentals including; routing functions, algorithms for assessing metric costs.
• Includes labs for these exercises.
• Includes STIGs, Access Control List and the interior gateway protocols Routing Information Protocol (RIP) is addressed.

Network Router

• Provides understanding of Layer 3 routing concepts.
• Provides understanding of basic router configuration as pertains to network interconnection in any environment.

Router Description

• A router is a Layer 3 networking device that uses IP addressing to forward packets between networks.
• It connects two or more lines from different networks, directs packets based on its routing table.
• Router components: external (physical connections) and internal (memory hierarchy).

External Components

• Console Port: configures the router locally.
• Auxiliary Port: allows remote configuration.
• Network Interfaces: Ethernet or Token Ring for LAN, synchronous serial for WAN, and Trivial File Transfer Protocol (TFTP) severs.

Internal Components

• ROM: diagnostic and boot up routines are stored.
• FLASH: internetwork Operating Systems (IOS), Manufacture memory.
• NVRAM: saves start up configuration file.
• RAM: Contains the file, IOS, routing tables, data.

Router Start-up

• The bootstrap program is run and ROM testing is conducted.
• IOS loads to the RAM after the NVRAM is backed up
• Volatile changes are made to the running-configuration files

Types of Gateways

• Interior Router: router in a LAN called.
• Exterior Router: directs packets between hosts in one LAN and hosts on another LAN.
• Border Routers/Gateways: connects LAN with Wide Area Network (WAN).

Gateways

• A device that converts data from one protocol or format to another.
• Internet routing devices called gateways, perform routing protocol functions between machines, these gateways may be within or between autonomous systems (AS).

Autonomous System (AS)

• Defined by RFC 1930, groups IP prefixes under a single routing policy.
• Areas are controlled under routing domains which can be multiple.

Interior Gateway

• Routing Information Protocol (RIP)
• Border routers move info and use Exterior Gateway Protocols like BGP for routing between autonomous systems.
• Directs routing for local traffic and WAN bound traffic from one area in an Air Force Base.

Default Gateway

• Router defined as an IP address serves as an access point to or from a network along with a path for an LAN.
• An address nearest the router interface to transmit traffic for remote networks.

Internetworking Challenges

• Implementing a function undertaking.
• Address: Connectivity, Reliability, Network, and Manageability, and Flexibility,

Network Segmentation

• Routers and switches primary to over come challenges.
• Used to isolate and segment a network into separate; broadcast domains and collision domains.

Network Segmentation

• Broadcast Domain: where routers breakdown and direct connect to host in LAN.
• Data Link Layer sends communications to devices and host.
• A common logical Layer addressing scheme is sent to all host, aka sharing a subnet.

Protocols

• Actual communication across is possible through protocols, such as:
• Internet protocols: TCP (transmission),IP suite
• Address identifies devices or a group dependent on various schemes.

Addressing

• Addresses are at respect to model data an Network Layers
• Addresses family or OSI

Physical Addressing

• A MAC address with a unique identifies Data-link
• Generally only has one network connection for a host

Network Addressing

• Network of logical addresses sends info across networks
• Work primary at Layer 3 of a model

Router Addressing

• Each interface on a device is uniquely ID'd by an MAC
• Path determination will determine optimal path router's will take

Packets Switching

• Layer determination requires resolution for any protocol addresses
• Mac will require changes for the outbound interface of the net hop.

Router Protocols

• Destines to the packets for a variety of reasons
• Router will use the listing tables that used previously to forward the packet.
• Can discorded base on a header as follow, the the version ,if life was sent short time.

Route & Protocols

• Stand alone protocols within 3
• Responsible layer protocol for the logical addresses that all routers use.

Address Protocol

• Key protocol are that works within Datalink and Network Layer that is called Address Resolution Protocol (ARP).
• ARP is implemented with protocol

Multiple Local Area Networks

• Address resolution works differently when Source Device broadcast and request.
• Routers that make all traffic destination

Hello Protocol

• Is another key Protocol that enables net devices can learn the MAC and the other network address on all the other routes.
• To identify each and every other using a process called neighbor discovery

Internet Control Message

• The protocols is LAN that sends message traffic
• The ICMPT sends a report about processing , and the source router advertisement.
• In general this is a the route is dynamic the the same,and every time.

Routing Protocols

• Can maintain tables along with what's use by them.
• What the algo is using the weigh in on a weighted area to calculate optimal paths

Routing Algorithms

• Initialize table which a
• The goals depends on affect or resources are that you using.

Distance Vector Algo

• Use approach than indicates
• Direction for the direction you're going.

Advantages

• Simple to configured and understood
• Not too much to maintain
• Lesser expenses.

DISADVANTAGES

• Limited because of the large networks.
• Subnet most the are the in the RIP1 protocol
• Updating for each broad cast with is there and what from.

Link Stay Algo

• There to short with the and path for every one available and the for new net work

Unit 4: Device Layers

• Focuses on the Cisco hierarchical design model with the core, distribution and access layers.

Hierarchical Model Layers

• Core Layer: High-speed backbone for transporting large amounts of traffic.
• Distribution Layer: Provides routing, filtering, and WAN access, determines how packets can access the core.
• Access Layer: Connects end-user computers to the network with hubs and switches.

Core Layer

• Speed: Designed with speed in mind and to eliminate traffic slowdown.
• Workgroups: No support for group work on devices can connect to the access layer.
• Scalability: Avoid expansion and upgrade to increase performance
• Redundancy: Consider high reliability, that can provide both fast and redundant such and fiber optics technology's.
• Select protocols lower for more convergence efficient layer to switching.

Distributions Layer

• Communication point between layers
• Filter and routing and WAN access

Policies

• Implement: Tools such list, filtering , queuing, security policy addresses, including walls.

Units Summary

• Examines the layers and the how that perform to do is the device that need to has or use.

Unit 5: Sub-Networks (Subnets)

• Covers subnetting, including why they're needed, how they work, and CIDR.

Subnets Overview

• Subnets are used because user programs need to talk to servers, and things that connect are referred to "hosts".
• Addresses have function of figuring and communication happens.

Subnets

• Separate and identifiable which by logically arranging connected network devices and dividing them from a network with addresses.

Of course the more bits, the less hosts

• Is what you the can on which be what means that and network the the the you want

Basic understanding

• The concept addresses must has, so you how it works

In what order, how many

With 3x8 as a basis to remember as.

Variable Length

• Subnet has VLSM if are.
• No rip address for this is has more 1 or more sub that

Planning A Simple Network

• And a with practice and a knowledge IP addresses
• Setting up subnetting and and to give a proper addre

Static vs Dynamic

• Two different of IP.

Unit 6: Network Diagrams

• covers physical logical and data flow.

Objectives

• To develop both physical, data, and logical diagrams, along with different instructors who are assisting.

Physical Drawing

• Actual physical arrangements to components, including hardware and cable.
• Layouts show plans of work floor

Physical topology

Refers of the interconnection of more, if any on network devices. This is what will be shown are on the nodes that are in contact to every others.

Star

This is what all to do with hubs as a part of any peripheral modes.

Mesh Topography

Which in case full the ,each and everyone will direct to one another.

Tree Topography

• The structure combines the has what is and bus
• The the of structure the topology which contains what a has is in it or structure with an tree