WEBVTT 00:00.290 --> 00:05.760 In this episode I want to do a quick review of a lot of important denizens of our local area network 00:05.920 --> 00:07.380 air go land review. 00:07.380 --> 00:12.540 So what I'd like to do right now is run through a lot of stuff on switches and routers and such that 00:12.630 --> 00:17.640 hopefully you would already know but for complete this let's just go ahead and do a quick review starting 00:17.640 --> 00:23.110 with switches. 00:23.170 --> 00:27.900 So what I have here in front of me is a pretty standard net gear switch. 00:27.910 --> 00:34.570 Now remember switches filter and forward data based on MAC addresses so switches tend to pretty much 00:34.570 --> 00:36.280 work automatically out of the box. 00:36.280 --> 00:41.270 However there are some features that we're going to see on the exam I want to just make sure you know. 00:41.290 --> 00:42.370 So let's go through those. 00:42.370 --> 00:44.890 The first one is the concept of a VPN. 00:44.890 --> 00:50.870 Now normally when I'm talking on this one switch it is one broadcast domain. 00:50.980 --> 00:54.280 So if somebody sends out a broadcast it goes out to every other port. 00:54.430 --> 01:01.570 However if we want to we can actually split up that single broadcast domain into multiple broadcast 01:01.570 --> 01:04.020 domains known as villans. 01:04.030 --> 01:09.960 So in essence what I can do is I can set up a VPN and villans have numbers you do like VLAN one Villiam 01:09.950 --> 01:10.630 too. 01:10.750 --> 01:12.200 You really can't say like Villiam. 01:12.200 --> 01:14.060 Timmy it doesn't work that way. 01:14.710 --> 01:21.370 But then once I create these villans I can then assign ports and in this case I could say I could take 01:21.370 --> 01:27.250 the first this is a 26 port switch I could take the first 12 ports and make it to be really on one and 01:27.250 --> 01:32.080 the rest of the ports be to be there in two and it would be as though I simply had two completely separate 01:32.080 --> 01:32.990 switches. 01:33.100 --> 01:39.620 So to see this what I've got is the configuration screen up so let's take a look over here. 01:39.700 --> 01:41.620 Now this machine is right out of the box. 01:41.620 --> 01:44.620 I have done really no configuration to it whatsoever. 01:44.620 --> 01:48.820 I also need to warn you as there are tons of settings in here that I am not going to be covering in 01:48.820 --> 01:53.430 a quick review we're just going to hit the ones that I want to make sure you're aware of for the exam. 01:53.440 --> 01:56.770 So first of all let's go over to switching now. 01:56.820 --> 02:00.900 If you take a look on this system I'm going to click on Vili's And here you'll see that it has three 02:00.900 --> 02:06.930 built in villans number one which is the default VLAN and then these two others which I doubt I would 02:06.930 --> 02:07.380 ever use. 02:07.380 --> 02:10.010 Voice of the land and audio land. 02:10.050 --> 02:14.730 The reason they're doing that is because it's very common if you're using voice over IP to put all your 02:14.730 --> 02:19.890 voice devices on their own separate VPN and in this case video as well. 02:19.890 --> 02:24.810 Now once you have these villans made and I can make my own villans if I want but let's just stick with 02:24.810 --> 02:26.210 these three for the moment. 02:26.220 --> 02:31.360 What I can now do is begin to assign different ports to different lands. 02:31.470 --> 02:33.750 So I'm going to come over here on this particular machine 02:36.420 --> 02:43.530 and see right here when I click on ports you can see right now they're basically not on any body at 02:43.530 --> 02:45.550 the moment or what we would call untagged. 02:45.570 --> 02:51.990 So if I want to put port 13 on a particular Vili's in this case to 02:54.750 --> 02:55.680 I'm going to go ahead 03:00.920 --> 03:02.190 hope there it is hit apply. 03:06.990 --> 03:13.350 And I now have put port 13 onto the second Vili's LAN The important thing you need to understand it 03:13.460 --> 03:20.630 villans is that the moment I put that port 13 onto a separate Villalon it will be as though it disappeared 03:20.630 --> 03:21.750 from the switch. 03:21.770 --> 03:27.150 The only way I could get other people to talk to it is if I put more ports onto that same plan. 03:27.350 --> 03:29.750 So villans are absolutely critical tool. 03:29.810 --> 03:35.480 It is the way we do what we call layer 2 separation of networks and it's an important security feature. 03:35.480 --> 03:43.760 Now the other security feature I want to talk about is flood gardi Now one of the dangers with switches 03:43.760 --> 03:48.500 is that you can accidentally plug them together in such a way that you can create loops or what we call 03:48.500 --> 03:49.630 bridge loops. 03:49.730 --> 03:53.900 Now a bridge loop will basically knock a network down instantaneously. 03:53.900 --> 04:01.240 So what we've developed with any good switch is something called spanning tree protocol or as t.p. 04:01.250 --> 04:06.500 So the nice part about the PC pretty much just have to turn it on and let's go back in here and let's 04:06.500 --> 04:09.250 make sure SEPs even lit up on these guys. 04:10.950 --> 04:14.530 So in this particular one there's a little tab for SDP. 04:14.640 --> 04:19.960 And as I look here right now SDP is disabled so I'm going to go ahead and turn that on. 04:20.070 --> 04:28.290 Now there's SCDP and then rapid SDP and we pretty much just use Rapide SDP and then PDU flooding is 04:28.290 --> 04:32.400 just if we moved boxes around it knows how to track that type of stuff. 04:32.400 --> 04:36.760 So really all I need to do in this particular case is make sure that this guy is turned on. 04:36.960 --> 04:40.800 So those are the two big things about switches I want to make sure that you're aware of. 04:40.800 --> 04:45.900 Number one this is where we set up the lands and then number two make sure that you're comfortable with 04:45.900 --> 04:49.830 the concept of SCDP and that it prevents loop floods. 04:49.830 --> 04:51.150 So that's a very very good thing. 04:51.150 --> 04:55.170 So let's go and do this one more time except this time let me replace this with a router 04:59.610 --> 05:06.660 it switches filter and forward based on mac address or Layer 2 routers filtered forward based on IP 05:06.660 --> 05:08.220 address or Layer 3. 05:08.220 --> 05:14.700 So the term layer 3 switch is a very common term that can be used interchangeably with the word router. 05:14.730 --> 05:22.560 So if routers filter and forward based on IP addresses routers are going to act as the doorway or the 05:22.560 --> 05:25.550 interface between different network IDs. 05:25.560 --> 05:26.900 So let's take a look at this. 05:26.940 --> 05:28.770 So here's a router that I have right now. 05:28.770 --> 05:35.070 And in this particular case this simple router is separating two different network IDs on one side is 05:35.080 --> 05:36.950 192 168 for. 05:37.020 --> 05:38.540 And we'll just put that 0 can there. 05:38.580 --> 05:40.010 Lots of computers in there. 05:40.110 --> 05:41.530 So it'll be 190 168. 05:41.540 --> 05:45.640 Forgot one for the router itself that 2.3 for whatever. 05:45.690 --> 05:54.450 And then on the other side it's going to be 10 11 12 0 so the router itself spans and filters and forwards 05:54.480 --> 05:57.660 IP addresses between these two different network IDs. 05:57.660 --> 05:59.520 Now don't think routers can only do two. 05:59.520 --> 06:04.980 For example let's do this again except this time let's span three different network IDs so here's a 06:04.980 --> 06:10.710 router that's separating three different network IDs routers can have lots and lots of different interfaces 06:10.710 --> 06:11.400 in them. 06:11.400 --> 06:18.270 Anyway let's go back to our original drawing now if a router is acting is what we call a gateway it 06:18.270 --> 06:23.550 is acting as the interface between your local area network and the big Internet of the cell so we call 06:23.550 --> 06:30.670 that a gateway router a gateway router will always be running the network address translation or nat. 06:30.750 --> 06:37.290 In that case our Internet service provider gives one IP address to the router and then the router converts 06:37.290 --> 06:43.950 that into a private IP address range which then passes out to the individual computers on the local 06:43.950 --> 06:44.870 area network. 06:44.970 --> 06:50.790 Now since this router is already connected to the internet it is very common for us to do something 06:50.790 --> 06:52.090 called a firewall. 06:52.350 --> 06:58.020 A firewall is a piece of software that is commonly run on a gateway router which protects us from the 06:58.020 --> 07:04.410 evils of the Internet so it can forward and filter based on port numbers based on IP addresses your 07:04.440 --> 07:06.350 Else all kinds of different stuff. 07:06.510 --> 07:12.360 So we would call this a network firewall because the gateway is running the firewall software and protecting 07:12.360 --> 07:14.490 us from the evil of the Internet. 07:14.490 --> 07:19.480 So this was a quick and dirty review of some of the terms that you're going to be seeing on the exam. 07:19.500 --> 07:24.090 I hope you're familiar with all these terms and can appreciate that I'm doing a very light touch to 07:24.090 --> 07:24.520 it. 07:24.520 --> 07:29.940 However if there are any terms that I just brought up that you're unaware of I wouldn't think it would 07:29.940 --> 07:36.450 be too bad of idea to consider for example my network plus video series to help you dial in and make 07:36.450 --> 07:55.040 sure you really understand what these switches and routers really do.