1 00:00:00,000 --> 00:00:00,499 2 00:00:00,499 --> 00:00:02,880 Once a network has a dozen or so routes, 3 00:00:02,880 --> 00:00:04,800 it's no longer reasonable and is kind of 4 00:00:04,800 --> 00:00:08,310 tedious, actually, to do manual configuration of static routes. 5 00:00:08,310 --> 00:00:09,960 So we're going to migrate or move 6 00:00:09,960 --> 00:00:11,580 to something more flexible. 7 00:00:11,580 --> 00:00:14,610 Specifically, dynamic routing protocols. 8 00:00:14,610 --> 00:00:16,620 So in this topology, I've taken the liberty 9 00:00:16,620 --> 00:00:19,140 of adding an additional router, router 3 and also 10 00:00:19,140 --> 00:00:20,530 some additional networks. 11 00:00:20,530 --> 00:00:25,110 So we've got the 10.1.0, 10.2.0, 10.3.0, 10.4.0, 10.5.0, 12 00:00:25,110 --> 00:00:30,720 also 10.6.0 between R1 and R3, 10.7.0 between R3 and R2, 13 00:00:30,720 --> 00:00:33,276 and the 10.8.0 network hanging off of R3. 14 00:00:33,276 --> 00:00:35,400 And the benefit of using a dynamic routing protocol 15 00:00:35,400 --> 00:00:36,900 is we can get these devices talking 16 00:00:36,900 --> 00:00:40,290 to each other to dynamically share information regarding 17 00:00:40,290 --> 00:00:42,810 what routes are reachable and through whom. 18 00:00:42,810 --> 00:00:44,520 And there's two major camps regarding 19 00:00:44,520 --> 00:00:45,670 dynamic routing protocols. 20 00:00:45,670 --> 00:00:47,700 There's distance vector. 21 00:00:47,700 --> 00:00:51,270 The classic example of that would be the RIP protocol-- 22 00:00:51,270 --> 00:00:52,450 may it rest in peace. 23 00:00:52,450 --> 00:00:54,402 It stands for Routing Information Protocol. 24 00:00:54,402 --> 00:00:55,860 And there's a couple flavors of it. 25 00:00:55,860 --> 00:00:57,570 There's version 1, and there's version 2. 26 00:00:57,570 --> 00:01:00,177 Most people are using version 2, if they're still using it. 27 00:01:00,177 --> 00:01:02,010 And with a distance vector routing protocol, 28 00:01:02,010 --> 00:01:03,200 it's routing by rumor. 29 00:01:03,200 --> 00:01:04,950 What do you mean, Keith, routing by rumor? 30 00:01:04,950 --> 00:01:08,550 Well, if R1 believes that he can reach the 10.1 network and 10.2 31 00:01:08,550 --> 00:01:11,182 network, he's going to go ahead and tell R2. 32 00:01:11,182 --> 00:01:13,140 And R2 says, great, thanks for the information. 33 00:01:13,140 --> 00:01:14,730 If I need to reach those networks or forward 34 00:01:14,730 --> 00:01:16,380 packets in those directions, I know 35 00:01:16,380 --> 00:01:17,940 I can use you as the next hop. 36 00:01:17,940 --> 00:01:20,230 And R2 can propagate that information to other router. 37 00:01:20,230 --> 00:01:25,680 So R2 can advertise to R3 the networks of 10.1.0 and 10.2.0, 38 00:01:25,680 --> 00:01:27,690 even though he doesn't have firsthand knowledge 39 00:01:27,690 --> 00:01:30,870 of those networks, he simply heard about them from R1. 40 00:01:30,870 --> 00:01:33,240 Another approach with dynamic routing protocols 41 00:01:33,240 --> 00:01:35,330 is link state routing protocols. 42 00:01:35,330 --> 00:01:36,990 And with link state routing protocols, 43 00:01:36,990 --> 00:01:39,690 we still have routers that are directly connected to networks 44 00:01:39,690 --> 00:01:42,030 except those routers advertised the states, 45 00:01:42,030 --> 00:01:43,740 the details regarding the networks 46 00:01:43,740 --> 00:01:44,900 that they're connected to. 47 00:01:44,900 --> 00:01:47,280 In one of the protocols, called OSPF, 48 00:01:47,280 --> 00:01:49,920 which is a very good example of a link state routing protocol-- 49 00:01:49,920 --> 00:01:53,200 OSPF is an acronym for Open Shortest Path First-- 50 00:01:53,200 --> 00:01:55,050 and with OSPF, the routers are going 51 00:01:55,050 --> 00:01:56,480 to send that little LSAs-- 52 00:01:56,480 --> 00:01:58,270 link state advertisements. 53 00:01:58,270 --> 00:02:00,640 In that way, R2 can take a look at the link state 54 00:02:00,640 --> 00:02:03,460 advertisements from R1 along with link state advertisements 55 00:02:03,460 --> 00:02:04,380 from everybody else. 56 00:02:04,380 --> 00:02:07,037 And then every router, based on all that data, 57 00:02:07,037 --> 00:02:09,120 can make their own calculations about the best way 58 00:02:09,120 --> 00:02:10,330 to get through the network. 59 00:02:10,330 --> 00:02:12,840 So we're not relying so much on rumor from a neighbor regarding 60 00:02:12,840 --> 00:02:15,423 everything behind that neighbor, a link state routing protocol 61 00:02:15,423 --> 00:02:19,470 is like OSPFR, more tight more concise and more accurate 62 00:02:19,470 --> 00:02:21,034 and usually, they converge faster. 63 00:02:21,034 --> 00:02:22,950 That means if there's a change in the network, 64 00:02:22,950 --> 00:02:24,491 the entire network will figure it out 65 00:02:24,491 --> 00:02:27,660 much faster than in a distance vector routing protocol. 66 00:02:27,660 --> 00:02:29,280 And then we also have some protocols 67 00:02:29,280 --> 00:02:30,950 in this group called hybrid. 68 00:02:30,950 --> 00:02:33,840 Now Cisco, a long time ago, created a routing protocol 69 00:02:33,840 --> 00:02:36,700 called EIGRP. 70 00:02:36,700 --> 00:02:38,430 And if you read Cisco's documentation, 71 00:02:38,430 --> 00:02:41,010 they're going to tell you, it's an advanced distance vector 72 00:02:41,010 --> 00:02:42,120 routing protocol. 73 00:02:42,120 --> 00:02:44,520 Because it uses all of the features of a distance vector 74 00:02:44,520 --> 00:02:46,980 routing protocol, but EIGRP also uses 75 00:02:46,980 --> 00:02:50,090 mechanisms that are similar to how a link state operates. 76 00:02:50,090 --> 00:02:52,650 So it can be referred to as an advanced distance vector 77 00:02:52,650 --> 00:02:54,192 or if you wanted to call it a hybrid, 78 00:02:54,192 --> 00:02:56,233 no one's really going to look twice if you put it 79 00:02:56,233 --> 00:02:57,570 in either of those categories. 80 00:02:57,570 --> 00:03:00,810 And one of the features of link state that EIGRP does use, 81 00:03:00,810 --> 00:03:03,450 they form like an official neighborship-- 82 00:03:03,450 --> 00:03:05,520 using that routing protocol with their neighbors. 83 00:03:05,520 --> 00:03:06,990 And that way if something changes, 84 00:03:06,990 --> 00:03:08,489 they can have very quick information 85 00:03:08,489 --> 00:03:11,100 about changing the topology and updating their routing table 86 00:03:11,100 --> 00:03:13,600 to reflect the correct routing tables through the network. 87 00:03:13,600 --> 00:03:15,600 And one other protocol I want to talk about here 88 00:03:15,600 --> 00:03:19,410 is BGP, the Border Gateway Protocol. 89 00:03:19,410 --> 00:03:22,350 And that's the protocol that we use on the internet today. 90 00:03:22,350 --> 00:03:26,070 And one interesting thing about BGP is that BGP neighbors-- 91 00:03:26,070 --> 00:03:28,360 two BGP speakers that are talking to each other-- 92 00:03:28,360 --> 00:03:30,570 they don't have to be directly connected 93 00:03:30,570 --> 00:03:31,750 or on the same network. 94 00:03:31,750 --> 00:03:34,030 So for example, we can have a router over here. 95 00:03:34,030 --> 00:03:35,310 Let's call it router 4. 96 00:03:35,310 --> 00:03:36,866 And up here, we can have router 5. 97 00:03:36,866 --> 00:03:38,490 And as long as they have reachability-- 98 00:03:38,490 --> 00:03:40,230 meaning they have connectivity to each other through 99 00:03:40,230 --> 00:03:41,070 the network-- 100 00:03:41,070 --> 00:03:43,950 they can establish a BGP neighborship, 101 00:03:43,950 --> 00:03:45,870 which makes it fairly unique compared 102 00:03:45,870 --> 00:03:49,030 to distance vector or a link state routing protocols. 103 00:03:49,030 --> 00:03:51,930 So we can put BGP if we wanted to also in that category called 104 00:03:51,930 --> 00:03:54,990 hybrid because it has some mechanisms that resemble 105 00:03:54,990 --> 00:03:56,940 distance vector protocols, and it also 106 00:03:56,940 --> 00:03:59,555 has things like neighborships that are similar to how 107 00:03:59,555 --> 00:04:01,110 link state protocols operate. 108 00:04:01,110 --> 00:04:03,600 And the benefit of using a dynamic routing protocol is 109 00:04:03,600 --> 00:04:06,960 that once we have configured the dynamic routing protocol, 110 00:04:06,960 --> 00:04:08,730 changes that are made on the network-- 111 00:04:08,730 --> 00:04:11,340 links coming up or links going down or new networks being 112 00:04:11,340 --> 00:04:12,030 added-- 113 00:04:12,030 --> 00:04:14,490 all that information can be dynamically communicated 114 00:04:14,490 --> 00:04:15,930 to the other routers, so we don't 115 00:04:15,930 --> 00:04:18,547 have to manually configure static routes. 116 00:04:18,547 --> 00:04:20,130 In this Nugget, we took a look at some 117 00:04:20,130 --> 00:04:23,670 of the categories and benefits of dynamic routing protocols. 118 00:04:23,670 --> 00:04:26,010 I hope this has been informative for you, 119 00:04:26,010 --> 00:04:29,510 and I'd like to thank you for viewing.