IT Ninjas: Mastering Network Troubleshooting in Windows

Hello and my name is Lowell Vanderpool and this channel is dedicated to IT professionals, IT students, and anyone who's interested in technical subjects. Troubleshooting network connectivity is probably the most common skill or task that an IT professional does at the help desk level or level one tech. It is just something you do on a regular basis. So learning to do it well is very very important. We're going to look at best practices. We're going to look at dealing with wired and wireless users. We're going to work look at working with remote and local users as far as troubleshooting network connectivity. We're going to look at PowerShell NetEsh tools to help you troubleshoot. Then I want to share from my experience different types of portable tools that you can carry with you to help you troubleshoot network connectivity issues. We're going to look at wireless interference as a big problem a big problem for wireless clients. We're going to look at wireless interference as it relates to troubleshooting a lot of their network connectivity or slow network connectivity. And then finally I'm going to share my favorite internet testing tools that I use to test the client's machine prior to leaving and clearing up that help desk ticket. I know that that system is working properly. We're going to be focusing on Windows 10. We'll be working from the simplest to the most complex solutions. We're going to look at items that anyone can try to steps that's best left to the IT professional. Below in the graphics is a cool thing for you geeks where it's a five-speed PCI Express x4 network card that covers from 1 gig to 2.5, 5 gigs and 10 gigs. Everybody wants that for Christmas. So before we jump into troubleshooting remember this new five-speed network cards and switches are out there and they are going to be coming to the enterprise at some point slowly at first but it will become the standard at some point. Remember you have to have at least cat 6 cable for 5 gigabits and at least cat 6a if you're going to get 10 gigabits. So just keep that in mind. Now if you're watching this video and you're neither an IT professional or you don't do this as a profession but you're watching this video hoping to solve the network connectivity then you need to determine whether you're wireless or wired. If you're in an office you're probably going to be connected to a network cable. If you're working from home and you're plugged directly with a cable in your router you're wired. If you have a laptop and you're at home you're probably gaining access to the network via wireless. If you have a tablet you're definitely going to be wireless. As an IT professional usually when I deal with wired clients I am usually going to get a phone call or I'm going to get an email from a co-worker saying that their buddy in the cubicle next door doesn't have internet access when I come look at it or a help desk ticket is generated or I'm tackled in the hallway. Usually tackled in the hallway. First thing I'm going to do is I'm going to ask them to see is the cable plugged in. Listen don't assume anything. Many times I solve problems right right here. Is the cable plugged into the back of the computer or is the cable plugged into your laptop. Now this has to be done with some carefulness. For example if it's a lady she's probably not going to crawl under the desk to check. So remember there's an appropriateness here. You may have to at some point get under the desk and look and yes you're going to dodge those moldy potato chips and 40 years of dust and grime. As you can see in this picture this particular PC is very typical in a workplace and it may have COVID-19, COVID-20 and a hundred other serious diseases that exist both above and below the desks. I've been to many of these. Remember many a good network cable has lost its life to the janitorial vacuum cleaner the night before. Check your cable. LEDs on computer equipment are for technicians. I make every student learn the LED indicators on any piece of equipment that we train them on from printers to network cards to the computer itself because those LEDs are for you the tech. You need to know what they are and what do those LEDs indicate. On the back of every network card are two LEDs. One LED is usually a solid color and this indicates what is known as link. Most cases it's green but many manufacturers use that same link LED with a multi-colored LED and it also indicates speed such as green for 10 megabits, amber for 100 megabits and yellow for a gig. Now there's usually one other LED and that indicates it flashes and it indicates ethernet traffic. It is very important that you look and see are those LEDs functioning correctly. Now on some low-cost low-cost PCs and laptops they have no LED indicator at all. Almost all enterprise switches have the same two LEDs both a link LED and an activity LED. It is very important you understand what they are. Let's understand your link LED. It's a series of unseen communication between your network card and your switch port. A booting PC or laptop NIC waits for and transmits these critical pulses to validate layer one is stable before it transmits data. This is all a part of auto negotiation between the NIC and the switch for link speed and duplex. The link information is encoded into a special pulse train known as FLP or fast link pulse. Each FLP burst consists of 33 pulse positions that provide clock and data information. Keep in mind your network card is responsible for getting the link lights on both the switch port and the network card and keeping them on. Now NIC or switch that fail to negotiate speed the link light will stay off. If the NIC or switch fail to negotiate duplex the link light will stay off even though both of them are connected. If either device the switch or the network card is powered off or if either device is being reset or reinitialized the link light will be off. So here we can see link and we see network activity. So you can see the one flashing showing you ethernet traffic and on the other side you see the link LED. Now I'm powering down the switch you see link light go out and I'm going to go ahead and plug the switch port back in and you'll see link light come back on. There it goes. An activity light once they become stable the pulse train goes they auto negotiate then you'll see your activity light kick on that is what you need to understand about your link light and activity lights. If you're on help desk or you're a tier one tech and you're helping a user on your local network either wired or wireless before you get up out of your chair and you go work with that user at their location make sure you try to connect to that PC remotely. So let's launch PowerShell and I'm going to launch PowerShell ISE and we're going to use test connection computer name and I'm going to type in the computer name that in this case this is a win10. Now I could have done a ping command but remember if you're not moving your skill set forward you're getting stuck behind. PowerShell is where Microsoft is going so start moving your skill set forward don't get stuck behind. So this is a simple tool it allows us to test layer one all the way through the our network card switches cables verify we connect to their network card. Layer two driver's network card. Layer three IP. This is a very good test if it fails and you know you have a connectivity issue before you get up out of your chair but test this before you go. The basics for wireless users is just checking to make sure you have connectivity so you open up your wireless menu option here and make sure your wi-fi is on not off make sure it's on and also make sure your airplane mode is not on because that will kill your wireless notice it automatically goes off. Again those are some real basics make sure that those conditions are appropriate. If you're dealing with wireless you should have a wireless icon here in the system tray you can click on it and it should show you a list of all the trusted access points that you can connect to. Even if it says connected you're connected to an access point here I'm connect go ahead and disconnect and then try connecting again. Sometimes that solves your connectivity problem if that doesn't you can always come down and find a 2.4 version of your same trusted access point and try connecting to that and again put in your network security key and try connecting to another but make sure you connect to only trusted devices. Now in terms of portable tools for network troubleshooting this product right here it's called a Linkrunner AT1000 it has a cousin called AT2000. These tools were originally designed by Fluke which sold this entire product line to NetScout and then NetScout spun them off to another company called NetAlly. They really haven't changed in their software or hardware they're absolutely awesome they give you everything you need as a level one help desk to troubleshoot network connectivity especially wired connectivity. Switch port name, VLAN, link speed, duplex, copper cable test, wire map for patch cables, cable length, you name it, power over ethernet they're amazing tools. They are pricey at $1,200 a pop you can get them probably discounted at different places these are well worth the money you spend on them. Again they have two versions they look into them if you're interested in a tool like this this is top of the line but is well worth the investment. Now this tool I have not used but it's very interesting basically it's a lower cost version of the Linkrunner it gives you link to switch test, DHCP validation, gateway information, internet connection, power over ethernet. What's really nice which I really was interested in this one was it sends it to your phone it gives you a 10 second test and it's under $500. So I haven't done this one myself but it looks very interesting and it's kind of tool that if your budget is tight but you need good network connectivity tools I would definitely check this out. Obviously you can go to Amazon and just type in network connectivity tester they have all kinds of product lines you have to do your homework and look at them carefully to make sure that they're going to meet your needs but there's some lower cost items that will help the IT professional do his job but honestly I've used the the Linkrunner it is the best tool out there for fast reliable effective troubleshooting and network connectivity. So check it out. So after we have checked network connectivity and the user very often is using a browser and that's what's not working make sure you've tested network connectivity everything looks okay and they're using Chrome to get to the internet to do whatever they're doing make them and Chrome is not still not working make sure you try an alternate browser try Edge try IE remember IE is buried under every version of Windows 10 you just have to type type it in and it will pop up but you can launch it so sometimes you can get the browser itself is in a failed state and it's the problem it's not the other issues that you've just tested and verified are good so try an alternate browser quickly to see if it is the browser that's a problem anyone who's troubleshooted non-connectivity also knows that malware and viruses can infect the user's machine and that can be an issue so you may have to stop at this point and look carefully at infections or malware in the system and see if you're infected that way. I have also experienced where users had expired antivirus products and those very nasty products would shut down web traffic usually you can tell that you've got an issue because you can ping but you can't browse with a with a browser be careful make sure they don't have an antivirus product that has quote expired and they I've seen a few that have been known to shut down web traffic you may have to rip those antivirus products out to get things going again. So let's get back to network troubleshooting if you're on the phone or you're at the user's desk you're going to go ahead and take and go to start go to settings and we're going to go to network and internet and we're just going to scroll down to network troubleshooting and launch network troubleshooter this is doing a lot of things so it's asking me questions here am I trying to read a specific website or folder because I'm really not having a problem it's saying why are you launching troubleshooter when there's no issue but this will actually kick off a series of scripts that will actually do a lot of things that I'm going to show you in the next slide so this is the next step you want to do for many IT pros you would prefer to do it manually so you can do you can open up PowerShell with admin rights and do a netash winsock reset a netash init ip reset ipconfig release ipconfig renew ipconfig flush dns those are really good steps that really reset a lot of the basic fundamentals of your network connectivity components if you'd like to run the network network troubleshooter right from a command line you can you can run a command called msdt.exe dash id and then type in network diagnostic network adapter and it actually runs that network troubleshooter for it pros I'm going to do two things this slide deck I'm actually going to put in the video description as an as a editable powerpoint slide as well as a pdf so if any of you would like a quick powerpoint that you could customize and send your users to help them troubleshoot on their own you're welcome to do that I'm also going to put the PowerShell netash tool document in rtf as well as pdf so if you'd like to edit it for your own use and add tools add additional features on your own you're welcome to do that it's great to be able to have a text document which you have commands for faster access I always carried a edited version of a notepad document with all my command line tools on a usb drive or a network share so I had quick access to it that prevents making typo errors that way I can just copy from the document paste it into the command line or the PowerShell and boom it works every time correctly so you've done the network connectivity troubleshooter and you're still not working and your user is at home or at a small business office let's take the next step so if you're still struggling with connectivity and you're at home or in a small office we're going to now reboot your router so your isp has a router generally a device that has both wireless and router functionality we want to unplug the power cable and let it totally de-energize some routers from your isp if you have voice over ip support they will put a battery backup you may have to remove that battery it's not difficult but look around and see if you can disengage the battery some do not some do it is very important that you let the modem come completely de-energized so pull power out wait 30 seconds we want those capacitors in that modem to totally de-energize before you plug the power back on that way the router will completely re-energize hardware and software know your isp modems led lights so when everything is working fine at home or at the office take a picture of your wire your isp modem so you know what the lights look like when everything is good things are not good and you see a light on that modem off when it should be on when you call tech support at least you're talking intelligently for it pros you have the same thing you have a d-mark zone in some place in your business environment where you have in this case you can see i've got fiber optics coming in and i've got a fiber optics terminal cable and then the fiber optics goes into an interface box all that belongs to the isp we're not to touch it but i take pictures of all those front facing leds and i know the condition of those lights when everything is normal if any light changes and we're having problems i can talk to tech support and say look this led is normally on this led is now off and usually the isp tech will then say oh yeah it's probably our side rather than them pointing figures and say well it's you guys's problem not ours etc etc be intelligent get your facts it saves a lot of problem on the tech support call okay mr vanderpool i'm still not getting anything or i'm still way too slow if you're still not having network connectivity let's uninstall the network card driver and reinstall it so i'm going to come over to my virtual machine and i'm going to type in device manager and i'm going to launch device manager and i'm simply going to come down to network adapters and find the network adapter that indicates that makes sense either an intel broadcom some network adapter that would be either your wireless or your wired network card you would right mouse click and you could uninstall device now if you do this in many cases this is going to edit your registry and possibly remove your driver so be careful if you're not sure how to install your driver you may want to be careful on this step i'm going to go ahead and uninstall and it's going to remove that entire device now i can come up back up and just say scan for hardware changes and notice it automatically puts it back in this is all done by plug and play you could also reboot your pc and it would put it back in so this is one option that you have for resetting your network card so we do have one more option so we're going to go back to start settings we're going to go to network and internet and if you scroll all the way down we have an option called network reset this is your last option because it can impact your vpn software and other software that you may be connecting back to your home network so if you're at home you want to be careful about doing this if there's a tech there that's an option he can definitely do this is going to be a pretty radical reset of your network system so this is an option we're going to click it and we're going to yep and it will basically reset everything regarding your network and log you off and reboot this is called the internet repair tool and it's a portable app it has been done by a developer who has maintained this for a long time and i've used this tool for many many years i'm not a big fan of these kind of tools but this one i have used personally make sure you do a restore point the developer encourages a restore point you don't just check all the boxes and hit go obviously an intention that there's intelligence behind a keyboard that's using a tool like this so you use only the most minimal tools as needed i would start at the top and work my way down and if you see something on that list that you know is not a problem don't try to fix it this is a good tool i've solved many many a problem with this tool so check it out it's worth looking into when it comes to wireless problems wireless interference in the home in the small office is probably the number one issue for slow traffic or no traffic so during covet 19 when everybody was sent home and became remote workers people bought new 4k tvs and more voice assistance security cameras and now they're they're trying to get on their work network and it's slow as molasses in january because they don't understand wireless there are lots of devices in a home that impact your wi-fi microwave ovens cordless phones tablets direct satellite service certain external electrical sources such as power lines electrical railroad tracks power stations wi-fi cameras baby monitors two-way radios remote controlled toys and on and on all can impact your wireless very often people will move their modem or their they move their home office behind a concrete wall that's in the back of the home or the back of the apartment and they wonder why they have no wi-fi it is very important that you understand what creates wireless interference i have two videos on my website and my channel that really cover wireless if you're an it pro wireless impacts your users more than anything else today and it's only going to grow in its importance not diminish get comfortable with wireless here's a great article on usb 3.1 devices using cables and how they interfere with wireless if you want to take a look and see this this is a very well positioned paper on poorly designed 3.1 jacks connectors and cables and how that can interfere with your wireless system for it pros microsoft has you has a great wireless report that you can kick off and then look at you use your netash commands as shown in this in this slide in the video description below i'll have a link to a pdf that will help you analyze this wireless report take a look at it very helpful dslreports.com is my favorite site for using to verify that the pc is functioning correctly it has fiber test cable test dsl test satellite test it also use multiple servers across the united states so i get a more accurate average of the thorough put up and down for that pc fast.com is a relatively newcomer to the internet speed test i like it because it is powered by netflix so it's good for testing video uploads and downloads it gives you both unloaded and loaded tests it also has settings that you can go in and modify and change for say a particular situation testmynet is another great site that gives you very accurate upload download and latency tests check it out this is a very interesting site with some really interesting results speedome is another site that you can test that internet connectivity i like this site it gives us seems to give a very accurate download upload and latency it also gives you your ip address