Time
5 hours 33 minutes
Difficulty
Beginner
CEU/CPE
3

Video Description

Troubleshooting Wireless and Wired Connections Part 2 Next we look at intermittent connectivity issues and what cause them to occur. For example, what happens when a firewall is misconfigured and block network access, about confirming the NIC card works, issues with the TCP/IP protocol stack, and why good troubleshooting practices always begins with eliminating or ruling out the obvious causes such as loose cabling, unplugged devices and other hardware related events. You learn about issues on the ISP side of connectivity and their related issues such as what happens when the wireless key information is entered incorrectly.

Video Transcription

00:04
Now we have intermittent connective ity. Intermittent connective ity means that we're able to connect sometimes and were not able to connect. Sometimes it may be flickering on and off now. This means this may be an issue for connecting with a wire to a wireless network. This may mean that our wireless network is out of range or that there's interference going on.
00:21
If we're connected to a wireless network and we're on the fringes of the edge of the wireless router,
00:26
then we may need to move closer. Or we may need to increase the power and the spread of the wireless range. If we can, we may want to move closer or increase the power to remove issues from interference, such as other devices. Other wireless routers, even things like
00:46
phone home wireless handsets for our phones
00:50
or garage door openers or microwaves can cause interference that may cause it's intermittent connective ity on our wireless. This maybe issues with some collisions that are happening on our network. We want to check and see if we have ah, lot of unnecessary activity going on on our network interface card. We're on our switches or routers to see If there's an issue there,
01:08
there may be some D. N s. Our firewall issues.
01:12
Our D. N s we've talked about is our domain name system domain name service that will help resolve our fully qualified domain names like google dot com to their i p address so that we can go out and find these websites and get to them. If our d. N s is malfunctioning, are we having? We're having issues with the N s.
01:30
We may have inner intermittent issues with connective ity to our Internet.
01:34
We may be having firewall issues. Our firewall may have certain settings on that block. Certain websites are maybe block certain ports or protocols, and we're trying to go to certain websites, and these firewall settings are preventing it or are preventing connective ity in our out. So they want to check on our firewall.
01:55
We have loose cable issues we may have if we're plugged in through a wired network. The cable itself plugged into our computer. Maybe, maybe loose. Ah, lot of people have seen situations where you have in the Ethernet cable you have a network cable and that clip on the back that holds it into your computer gets broken. It's very easy to happen,
02:15
Um, and if that clip is broken and you try to put the cable back in the computer, it can very easily just sort of
02:21
slide out eventually. And when that happens, we'll be having intermittent connectivity issues, especially if the cable is still sort of kind of in there and sort of making a contact. But every slight movement makes it move around just enough that you lose connectivity.
02:36
There may be Internet service provider issues I S P issues your local in, and that service provider may be performing line maintenance if they're storming, going on outside and you have
02:47
wireless connectivity. If you have Internet connectivity through, say, ah, hot spot that connects to a satellite and there's storming conditions going on and they actually be the storms that are causing the issues or storms on power lines that are also carry our carry fiber optic cables or Internet cables.
03:07
So we need to
03:08
I know that sometimes the Internet service provider issues if we're having Internet intermittent connective ity. If we're having intermittent connective iti just getting out to the Internet, getting out to things that are outside of our network, then that is probably our Internet service provider. Or maybe the modem that's on the outskirts of our network.
03:28
That may be having an issue,
03:30
but if we're if we're having connectivity issues inside of our network, then it's more than likely not. Our Internet service provider is probably something inside of our network that's going on
03:38
and then, lastly, we have network into fur face card malfunctions are T C P I. P. Stack malfunctions or corruption. So we want to check our network interface card. Maybe we want to try to use a loop back plug to do ah configuration test of our network interface card or possibly replace it if need be. We want to check our T c p i p stat
03:59
are
04:00
T C P I. P is what allows us to send to receive Internet protocol. Basically. So
04:09
with our T c p I p stack, we can re reinstall that we can on this solemn, reinstall, unload and reload R T c P I p stack, and that may solve some issues if that's what's causing our problem,
04:20
and then we have limited, limited connectivity. Ah, lot of times when we're trying to connect to a network, we may see our what looks like our monitor with a network cable plugged into it. And then we may see a triangle, an exclamation point and limited connectivity
04:40
that term exactly next to our network connection. Now, limited connectivity means that we're not receiving data. We're not receiving the data that our computers looking for, but we still think we're connected to the cable were connected to the wireless access point. So this may be an Internet service provider issue,
04:59
maybe our Internet service provider. Check with our Internet service provider to see if
05:03
the Internet coming into us is having issues or they're having issues and maybe our cable. The cable may be incorrect type of cable. I may not be a straight through cable, maybe a crossover, and maybe we may have grabbed a crossover cable by accident. Or maybe the cable has punched down that are a isn't Quint
05:23
exactly right, and that may cause some issues with limited connectivity. We want to check the switch router in firewall. All of those are locations where we may be having issues that may be causing our limits. Connectivity if we connect our computer to a switch and that switch then connects to a firewall,
05:41
we may have limited connectivity because we can connect to the switch and connect to other computers on our network.
05:46
But then the switch, for some reason, can't connect to the firewall. So we have to check all the steps in between where the Internet comes into our location to us and because all of those are possible locations for Internet connectivity failure. We'll talk about some tools, such as Ping in a little bit
06:02
in order to help better diagnose where our problem might be.
06:08
So we'll check our switch, router and firewall. Any of these three things can cause it's limited connectivity. Certain security settings on our firewall or certain filtering on our router may prevent us from getting out to the Internet, may limit the connectivity that we have and thus give us that message.
06:25
And if we're connecting to the wireless, we also want to check our wireless key.
06:29
Our wireless key is that password that we enter in when we're trying to connect to a password protected wireless network. If we enter that key incorrectly, ah, lot of times will get a response back that says you entered the incorrect wireless key. Sometimes, however, we may get what looks like a connection but says limited connectivity.
06:46
But we may have actually entered that wireless key incorrectly. So we want to check and make sure that that wireless key is correct.
06:53
We may need to check we named Manny to change the type of encryption that we're using to connect to that wireless access point. We may have selected the wrong encryption than the wireless access point or it made. Our computer may not be negotiating properly without wireless access point. Or there may be a Mac address filtering going on.
07:11
Whether it's a hardware five hard
07:14
hardware router with that were connected to with a cable or wireless router that were connected to wirelessly Mac filtering could be enabled and could be causing that limited connectivity

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Instructed By

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Anthony Harris
Systems Analyst and Administrator at SAIC
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