1 00:00:00,960 --> 00:00:07,200 So far in this course we have learned about how network endpoints create data and utilize different 2 00:00:07,200 --> 00:00:12,440 network protocols behind us and point data from one host to another. 3 00:00:12,450 --> 00:00:15,660 This is where network devices come into play. 4 00:00:15,660 --> 00:00:21,900 There are many networked devices in our networks and each of them play a specific role to forward traffic 5 00:00:21,990 --> 00:00:23,960 between endpoints. 6 00:00:23,970 --> 00:00:30,000 Here are some of the most common now work devices that are on almost every network. 7 00:00:30,000 --> 00:00:34,580 Let's take a brief look at each of these now devices. 8 00:00:34,830 --> 00:00:41,880 The first network device we're going to talk about are hubs hubs are legacy layer 1 devices that were 9 00:00:41,880 --> 00:00:47,290 used to just simply interconnect devices so that they can communicate with each other. 10 00:00:47,970 --> 00:00:53,760 So like in the slide if I wanted these two computers and this printer to be able to talk I could plug 11 00:00:53,760 --> 00:00:57,190 them into a hub and they would be able to reach each other. 12 00:00:57,750 --> 00:01:05,070 Well the problem with hubs is that unlike modern day switches they didn't have any intelligence on how 13 00:01:05,070 --> 00:01:15,030 to forward frame's hubs work by simply forwarding any received frames of all interfaces which is a terrible 14 00:01:15,030 --> 00:01:21,600 design because regardless of which endpoint the frame was destined to every host on the network receives 15 00:01:21,600 --> 00:01:23,500 a copy of the frame. 16 00:01:23,520 --> 00:01:26,830 This can obviously degrade performance on the network. 17 00:01:27,680 --> 00:01:36,090 Well to solve this problem switches were introduced switches forward layer to either not frames between 18 00:01:36,090 --> 00:01:43,840 switch ports based on MAC addresses once a switch learns a MAC address it can determine which switch 19 00:01:43,840 --> 00:01:48,600 poor to afford the frame out of based on its MAC address table entry. 20 00:01:48,850 --> 00:01:52,590 Also known as the camp table. 21 00:01:52,640 --> 00:01:58,600 So in this example based on the MAC address table entries that the switch has it would know to forward 22 00:01:58,750 --> 00:02:04,490 two frames dust into the phone on a port 1 0 8. 23 00:02:04,490 --> 00:02:12,500 One very important switching concept is a broadcast domain a broadcast domain as a boundary for layer 24 00:02:12,500 --> 00:02:17,190 to traffic when a broadcast frame is forwarded onto a LAN. 25 00:02:17,360 --> 00:02:20,960 It can only be sent within its local broadcast domain. 26 00:02:22,780 --> 00:02:30,280 Broadcast domains can improve network performance and security by limiting traffic between hosts to 27 00:02:30,280 --> 00:02:33,280 create multiple broadcast domains on a switch. 28 00:02:33,280 --> 00:02:42,240 The lands are used villans archaeological division of labor to traffic within a switch network. 29 00:02:42,340 --> 00:02:46,630 They are frequently used to secure traffic at a layer 2 level. 30 00:02:46,720 --> 00:02:53,680 For example if I had servers and guest devices coexisting on my corporate network I would not want the 31 00:02:53,680 --> 00:02:59,200 potentially vulnerable guest devices to be able to talk to my secure servers. 32 00:02:59,290 --> 00:03:05,020 So by simply placing these different traffic types on separate villans you can begin to enforce traffic 33 00:03:05,020 --> 00:03:08,480 borders to help secure the network. 34 00:03:08,550 --> 00:03:17,140 Avi plan best practice is to actually assign different villains to each device type. 35 00:03:17,150 --> 00:03:18,880 Next we have routers. 36 00:03:19,130 --> 00:03:24,080 Routers are used to route IP packets between different networks. 37 00:03:26,710 --> 00:03:33,910 The entire internet is actually made up of thousands of routers used to sign IP packets between houses 38 00:03:34,300 --> 00:03:40,910 and Web sites like Google and Facebook. 39 00:03:41,080 --> 00:03:47,200 Even though routers are primarily used to route IP packets they can also be used to secure networks 40 00:03:47,410 --> 00:03:52,950 with features like IP filtering and IPX. 41 00:03:52,960 --> 00:03:59,980 Finally we have wireless devices wireless connectivity is a major concern when it comes to securing 42 00:03:59,980 --> 00:04:08,660 a network and should be protected with strong encryption and authentication methods wireless access 43 00:04:08,660 --> 00:04:15,080 point deployments can be Autonomy's or lightweight autonomous apes are configured and managed individually 44 00:04:15,470 --> 00:04:24,050 and do not scale well lightweight APC's are centrally controlled by a wireless LAN controller for security 45 00:04:24,050 --> 00:04:24,680 alone. 46 00:04:24,680 --> 00:04:32,030 This is a big advantage for monitoring and maintaining consistent secure configurations across the wireless 47 00:04:32,030 --> 00:04:32,780 network. 48 00:04:34,910 --> 00:04:40,190 Now that you know what networks are and how they work you're ready to learn how to protect them in the 49 00:04:40,190 --> 00:04:41,250 next section. 50 00:04:41,270 --> 00:04:46,190 We will talk about network security devices like firewalls and IP UPSs.