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In this lesson,

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we're going to discuss packet loss.

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Packet loss occurs when data packets

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traveling across a network

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fail to reach their intended destination.

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When packet loss occurs,

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the quality of your data transmission

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is going to be affected, and this can lead to issues

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like slow internet speeds,

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lags in your video or audio streaming,

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and even complete disruptions

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to your network's communication.

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Now when packet loss is occurring,

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you may notice that some common symptoms

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like unexplained network slowdowns,

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jitter during VoIP calls and abrupt disconnections

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in your streaming media playback can occur.

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All these symptoms can disrupt your end user's experience

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and can lead to a significant loss of productivity

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within your organization.

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Now, there are many different causes

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associated with packet loss, including network congestion,

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faulty router configurations, bad cables,

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and hardware failures.

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Let's take a look at each of these.

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First, we have network congestion.

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Network congestion occurs when too much data

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is being sent through a network

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that exceeds the network's handling capacity.

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I want you to think about this like a traffic jam

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on your local highway when there are simply

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too many cars trying to drive down the highway

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in the same direction, and this causes slowdowns

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or even a complete stop to the traffic flow

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on that given highway.

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For example, if you're trying to stream a live sports event

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while sitting in your office,

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but everybody else is trying to do the same thing

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with other streaming media programs at the same time,

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this will cause your network to slow down,

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and in turn cause delays in all of our streaming services.

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Second, we have a faulty router configuration.

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Now, a faulty router configuration

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will occur whenever your routers are set up incorrectly,

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and this can lead to your data being misdirected

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or not get prioritized properly by your systems.

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For example, if I was going to give you directions

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on how to drive from Florida to New York,

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but I gave you bad directions,

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you may end up taking a longer route,

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or you may end up completely

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in a different location than you intended.

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This is why routers must be configured

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with the correct routes so that our network traffic

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can be routed and passed to the correct devices

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in order to complete any requested data transfers

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that you may be attempting on your network.

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Third, we have bad cables.

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Bad cables are physically damaged or deteriorating wires

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that will disrupt network data transmissions.

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I like to think about this like a leaking pipe

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under my bathroom sink.

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Sure, the water will still flow through the pipe mostly,

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but there is an integrity issue here,

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and some of the water may also drip out of the pipes

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and end up on my bathroom floor.

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So while the data may still flow within a bad cable,

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it can also lead to packet losses

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because some of that data will get dropped

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due to the bad cabling

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before it can actually reach its final destination.

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Fourth, we have hardware failures.

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Now, hardware failures occur when network devices

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like switches, routers, or modems malfunction.

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This is pretty obvious, but if our network devices

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that control the transmission of our data are failing,

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this is going to lead to packet loss

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and failed data transmissions.

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Now, to effectively troubleshoot packet loss,

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we first have to identify the source of that packet loss.

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To do this, we'll rely on command line tools

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like ping and traceroute.

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Now, the ping command will help us determine

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if the reachability of a specific device on the network

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does exist, and Traceroute is going to be used

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to map the path that your data is going to take

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to reach its intended destination.

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By conducting an analysis of your ping

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and traceroute results, you're going to quickly be able

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to determine where packets might be dropping

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as they're passing across your network.

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Another great, aid to determining

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where your packets are being lost

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is the use of network monitoring tools.

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This is because our network monitoring tools

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can provide more comprehensive insights

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into our traffic pattern in order to help us

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pinpoint the exact location and the potential cause

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of the packet loss being experienced on your network.

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After you complete your diagnosis

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of the root cause of the packet loss,

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you're going to want to begin implementing some of the strategies

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to mitigate and resolve this issue.

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If you're trying to solve a network congestion issue,

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then you should consider increasing bandwidth,

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optimizing the network layout,

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or employing better quality of service

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or QoS configuration settings

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to prioritize your most critical traffic.

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If you're trying to solve a hardware issue,

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then you really should be routinely inspecting

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and replacing faulty cables

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to ensure that your network devices

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like your routers and switches

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are going to be functioning correctly

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as they're passing the data between them.

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Also, if your hardware isn't operating as you expect it to,

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you may want to check to see

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if your device needs a firmware update

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that needs to be implemented in order to resolve

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any known issues that could be causing

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packet losses to occur.

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Now, if you're dealing with configuration errors,

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then you need to verify your configuration settings

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across all of your network devices.

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If you have any incorrect settings,

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this can often lead to packet loss as well.

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To fix it, you simply need to ensure that your devices

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are correctly configured for the network

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they're operating within, and this will help prevent

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packet loss from occurring due to a configuration error.

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Finally, it's important to implement some proactive measures

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to help prevent packet loss from occurring

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inside of your network.

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You should always implement

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regular network performance monitoring

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to help you identify issues before they escalate

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into larger scale and more significant problems

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across your network.

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By keeping your network infrastructure updated

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and well maintained, you'll also be able to reduce the risk

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of hardware induced packet losses inside of those networks.

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Also, you should always maintain a well-documented

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network configuration policy to prevent misconfigurations

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because these misconfigurations can often result

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in packet losses as well.

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So remember, packet loss occurs

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when data packets traveling across a network

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fail to reach their intended destination.

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These packet losses can significantly degrade

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our network's performance,

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and it will affect everything from simple web browsing

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to your most critical business functions.

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For this reason, it's critically important

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that you understand the symptoms, potential causes,

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and troubleshooting methodologies

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that you can use to identify and resolve

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any packet loss issues on your networks.