Common Troubleshooting Tools

I am a tool guy. I love tools. I've even got some of the tools here and I'm going to show you.

Documentation

Just a brief mention about documentation, because it's really important that all that work that you go into making documentation before there's an issue is really going to help you troubleshoot and come down to answers quickly when you're troubleshooting and things are on fire and things are crazy. I can't stress documentation enough. Make sure you have good documentation about your networks.

LED status indicators

Most of your equipment comes with some sort of LED status indicator, so make sure that you're familiar with those. On these particular switches, in the top left-hand corner you can see some indicators on how the switch is performing, and then across the bottom next to the ports you can see how the ports are performing. There is even some LED lights on the back that tell you about power and some other things. So there are some LED statuses that will tell you what is happening on the different equipment. And even in your PCs, if you look on the back with the NIC card, there's a good chance that there's an LED indicating that it's active and it's functioning correctly.

Cabling tools

As far as cabling tools go, this is not a pair of scissors. This is snips. This is to cut cable and cut pairs of wire. It even has a little notch out here that I can strip some wire with, if I need to go and strip just the outer sheathing off of the wire itself.

Or if I need to strip the sheathing around the cable, I have a special tool. This is a little razor blade that's in there, and this is a little piece of metal that just keeps it tight against there. Then you roll this around the cable and that sheathing will come right off. You can set the depth to make sure that it doesn't go too far and dig into the conductors, because you don't want it to dig into the conductors.

I also showed this crimping tool that allows you to put an RJ45 end in here, put the cables into there, and then crimp that down. I also have one on here for RJ11, and then it's got a spot here where I can actually just cut the cable, so I can put it in there and cut the cable. Although I rarely use that; I try to use the snips.

Those are some things I've already covered before. One thing I haven't covered yet is this punchdown tool. The reason why it's called the punchdown is because you take it and you push on it and it makes a little clicking sound. It's actually kind of a little hammer that just punches down on it, and it puts just the right amount of force on those cables. What it actually does is, there's little conductors that the cable goes into, and it peels away the insulator around the conductor and then makes a connection there. So this tool just pushes it down, and there's a little snip on it as well that shears that end off and pinches that end off, so that way you don't have the extra ends to it. Makes it look sharp. You would use this like on the keystone jacks when you're creating the jacks: then you'd punch this down onto there. Or if you're working with 66 blocks, or if you're working with 110 blocks, this is what you'd use to punch that down. You can even make some adjustments to it on how hard it actually punches that down. I have definitely used that in the past. It can be very helpful.

Some things that you'll see maybe in your textbook, or see out there, can definitely be helpful, but I don't know if I've really used this from a networking standpoint. This is a wire cutter and stripper here. There's a wire cutter right here. The next little section on here will crimp certain connectors and certain ends. And then this section right here will actually strip the wire; it is for different gauges, and you can strip the insulation off the wire. So this is a tool that you could possibly see out there as well. I once again don't really see it. I probably used it for some of the shielding, and getting the shielding grounded, but I haven't really used this for cabling.

If you're looking at it from a cable perspective, you may need something like this. This is for your RG6. You put your RG6 in here, put the end in here, and then this would crimp that together. So this is one for cable, like the cable that comes from the cable company, and then to put ends onto those. Those are some of the things that you would see with the cabling tools.

Another thing for cabling as well is you may see some fish tape. The fish tape is a stiff cable, and you take it out and you can fish this cable through walls and through ceilings. This is 100 ft. What you would do is you'd take the route that you want the cable to go, and you'd fish it through all of that. Then you would tape it. I've got some electricians tape here, and I'd tape the cable to the end of that. Then I would pull that cable back through, to get it through maybe through ceilings or through walls, or to get it through tight places that you can't really actually get to and physically put the cable in there. You'd be able to do it with this.

When you're splicing fiber, it's a little more tricky. You need something like this fusion splicer. Here you can see the two cables that are coming into it. What it does is it precisely cuts the ends, because you need to have them exactly at that 90 degree angle. So it cuts the ends, polishes the ends, and then fuses those together. That's a fusion splicer, and it's a little more complicated than doing like an RJ45 end.

Line testing tools

There's a lot of equipment when it comes to testing this cabling. Here's an example of this. I actually used this to test the RJ45 ends that we put onto it. You put the RJ45 into here, you put a connector on the other side, and then it'll tell you if you've got continuity, and it'll tell you if you've got any of your wires crossed. So this is a very helpful tool.

Another thing that I found to be very helpful, and I think this thing is awesome. I don't really see it as much in networking equipment, or in books and in some of the curriculum and stuff, but it's been something that I've used a lot and is really helpful. This is to find the cable lines. You have jacks in your different rooms that you're going to plug your computers and your phones and your different end devices into, and it then goes back to a network closet. But it can be sometimes hard, if it's not properly labeled, to know which is associated with that jack. So if you're trying to make that jack live and trying to figure out where that jack goes, what you can do is you can plug this RJ45 into the end of it, and then I can click this to generate a tone, and it's going to generate a tone on that line. Then what I'll do is, on the other side within the network closet, I'll start going and testing out the different lines. And then when I hit the one that has the line that I'm generating the tone on, it's going to be very loud. So I can positively identify that is the line, without having to do a lot of troubleshooting and a lot of running back and forth. So that can be an awesome tool to help you out.

Another thing that I really like as well is just something that tests the power. This is just a simple light. You plug it in, and if the light turns on, then you're good to go. It actually does a couple of other things and can tell you if your wires are crossed from your power perspective. So it'll do a couple of other things, but this is a great cheap way to test your power to make sure that your power is working.

You'll notice a lot of the content does talk about multimeters. This is a digital multimeter, and this is an analog multimeter. They serve really the same purposes. They just, one reads out digitally and one reads out from an analog perspective. What it can do is it can measure things like continuity, which continuity means is it passing power through it, or is there some sort of open connection. It will register zero if there's no connection at all, or it'll say yes, there is a connection and power is flowing through it. It also measures things like ohms and voltage and amps, so it can measure other things as well. This is listed out in a lot of the networking equipment books, but I really have not used this at all from a networking perspective. I use both of these a lot, but not from a networking perspective. So just realize that that is something that you may need to know for some of your tests, but you probably won't use it, or I at least have not used it out there in the field.

There are spectrum analyzers that you can plug into your networks. Whether it's a spectrum analyzer or portable network analyzer, they're ways to analyze the signal that's going across using that. This is going to be a little more expensive of equipment to use. I have not actually used a spectrum analyzer for networking, not at least from an Ethernet perspective. I have used spectrum analyzers for wireless, and I've gotten on to wireless networks to analyze wireless networks. So realize this could be something that you encounter. I don't see it as a common thing. One reason is because of the expense of the equipment, but you may see it out there.

Then you have something like a loopback adapter. A loopback adapter just takes the wires and takes the transmit and turns it into a receive. Or in the case of fiber, it just takes the transmit from the fiber and reroutes it to the receive of the fiber of the same connection. So that's really the idea behind this loopback adapter. It's the same connection, and you just plug it in, and it just tests that connection to see if that piece of equipment is even working correctly. Here's an example of it right here. This is a loopback adapter that comes with that tester for the cable ends. So you plug this on one end, you plug this on the other end, and then that tests that cable out. Or if I'm plugging into a jack, maybe I wired up a jack, then I've got a little adapter here that I can plug in there and measure that. So that's a loopback adapter, and it just takes the transmit and reroutes it to the receive.

Once again, fiber does take special equipment. That's where you have things like the OTDR, the optical time domain reflectometer, and there's a fiber light meter. Those are just ways to make sure that the fiber cable is at spec, or at a required level for network traffic to go across it. So that is some other tools that you may use out there if you're working with fiber consistently.

Network taps

Then we have network taps. A network tap is like a phone tap, where you are connecting into the connection and then you're listening to the traffic that goes across it. Let me give an example here. Maybe I want to listen into what this PC is saying. What I would do is I'd reroute the traffic to this network tap. And what essentially it really is, is just a hub, right? So then I reroute to here and then route into my main switch. And then I would have a piece of equipment hanging off of it that is then analyzing that traffic, and I can see that traffic that's going across it.

You can do the same thing with a lot of these smarter switches, where you're going to say, well, this is coming in on FA0. Maybe this is port five right here. And I'm going to mimic that traffic on FA0. Let's say it's FA022. And then I have a machine out there that's capturing that data, and then I can go in there and analyze and see. Maybe I'm troubleshooting some sort of issue that's going on and I want to really see the traffic, or maybe I want to see what kind of security stuff's happening on my switches. So I can do that to be able to analyze that traffic.

One other practical way that I've actually used this port mirroring before is that I've worked for schools in the past that needed to be able to monitor their students and make sure they're not going to sites that they're not supposed to. There's actually a few different ways that you can do that, but one of the ways that I did was, all the traffic that was going out to the external sources would have a copy of it sent to what's called a Websense server, which is a product that does web filtering. What would happen is all the traffic that was going to the outside would also be directed to this Websense. This Websense would look it up and see where the students were trying to go, and then if it was somewhere where they shouldn't be going, before the traffic came back from that other web page, it would send a web page to the client and say, "You're not supposed to be going to this site. We're going to log this and then let the administrators know that you're going to the site." So that's Websense right there. And it was commonly implemented in K-12 schools that were required to do some sort of filtering for their students. So that's a network tap. Essentially, a network tap is a way to listen into some of the traffic that's going across one of those ports.

I'm going to give an honorable mention to the screwdriver and the drill, because there are times when there's definitely unscrewing equipment from a rack where you need a screwdriver, or even a drill would be even more handy to make quick work of it.