1 00:00:00,000 --> 00:00:02,838 [MUSIC PLAYING] 2 00:00:02,838 --> 00:00:08,050 3 00:00:08,050 --> 00:00:10,480 So now that we've discussed all of the components 4 00:00:10,480 --> 00:00:14,410 necessary to support these additional applications 5 00:00:14,410 --> 00:00:18,700 on MPLS, let's go ahead and start talking about some 6 00:00:18,700 --> 00:00:20,770 of those additional applications. 7 00:00:20,770 --> 00:00:24,250 We'll begin by talking about VPNs. 8 00:00:24,250 --> 00:00:26,530 Now, as we mentioned a little bit earlier, 9 00:00:26,530 --> 00:00:31,270 we do, in fact, support both Layer 2 and Layer 3 VPNs. 10 00:00:31,270 --> 00:00:36,100 And in this video, we're going to get an introduction to VPNs. 11 00:00:36,100 --> 00:00:38,590 Now, keep in mind as we go through here, 12 00:00:38,590 --> 00:00:42,460 this is just getting us familiar with the concept of how 13 00:00:42,460 --> 00:00:45,430 these work, and a little bit of their attributes. 14 00:00:45,430 --> 00:00:51,482 We have full skills coming up on both Layer 2 and Layer 3 15 00:00:51,482 --> 00:00:53,990 VPNs in this domain. 16 00:00:53,990 --> 00:00:56,500 So again, keep in mind as we jump in here, 17 00:00:56,500 --> 00:00:58,690 that this is just an introduction 18 00:00:58,690 --> 00:01:00,490 to the overall idea. 19 00:01:00,490 --> 00:01:04,120 On that note, let's go ahead and jump in, and take a look 20 00:01:04,120 --> 00:01:06,650 at that overview. 21 00:01:06,650 --> 00:01:10,570 So let's begin our discussion of MPLS VPNs 22 00:01:10,570 --> 00:01:15,730 by talking about the attributes of Layer 2 VPNs. 23 00:01:15,730 --> 00:01:21,850 So the first is, these offer a more traditional type 24 00:01:21,850 --> 00:01:23,950 WAN connection. 25 00:01:23,950 --> 00:01:26,860 Essentially, what this is going to look like to the customer-- 26 00:01:26,860 --> 00:01:30,490 if they have two remote routers, and they're 27 00:01:30,490 --> 00:01:34,840 connected with a Layer 2 VPN, that Layer 2 VPN 28 00:01:34,840 --> 00:01:38,200 is ultimately just going to look like an Ethernet 29 00:01:38,200 --> 00:01:40,010 connection between them. 30 00:01:40,010 --> 00:01:43,070 So if they were running something, for example, 31 00:01:43,070 --> 00:01:47,620 like OSPF, their routers would become neighbors 32 00:01:47,620 --> 00:01:49,210 with each other. 33 00:01:49,210 --> 00:01:54,550 The entire transport looks like one big Ethernet cable. 34 00:01:54,550 --> 00:01:56,920 One of the main reasons this is advantageous 35 00:01:56,920 --> 00:02:01,150 for the customer is, again, this is very, very similar 36 00:02:01,150 --> 00:02:03,590 to traditional WAN services. 37 00:02:03,590 --> 00:02:06,730 In other words, they're familiar with this. 38 00:02:06,730 --> 00:02:09,160 Now, technically, this encapsulation 39 00:02:09,160 --> 00:02:13,580 can either be the same or different on each end. 40 00:02:13,580 --> 00:02:18,700 Now, the example I just drew is showing Ethernet on both sides. 41 00:02:18,700 --> 00:02:21,610 What we're saying here is maybe one side could be Ethernet. 42 00:02:21,610 --> 00:02:24,370 The other side could be something like frame relay. 43 00:02:24,370 --> 00:02:27,460 It doesn't matter what the actual encapsulation is. 44 00:02:27,460 --> 00:02:29,920 The point is, there's no routing in the middle. 45 00:02:29,920 --> 00:02:33,590 The devices will look like they're directly connected. 46 00:02:33,590 --> 00:02:35,740 Now, very commonly, this is going 47 00:02:35,740 --> 00:02:38,440 to be used to carry Ethernet. 48 00:02:38,440 --> 00:02:42,520 But as I just said, some of those legacy encapsulations, 49 00:02:42,520 --> 00:02:46,690 like possibly frame relay, or even ATM, 50 00:02:46,690 --> 00:02:49,100 can still be supported. 51 00:02:49,100 --> 00:02:51,400 Now, one of the main defining characteristics 52 00:02:51,400 --> 00:02:55,910 here of the Layer 2 VPN is we don't have any Layer 53 00:02:55,910 --> 00:02:59,080 3 with the service provider. 54 00:02:59,080 --> 00:03:04,750 All of the Layer 3 is happening between the customer devices. 55 00:03:04,750 --> 00:03:06,490 The service provider in the middle 56 00:03:06,490 --> 00:03:10,130 here is not involved in Layer 3 at all. 57 00:03:10,130 --> 00:03:12,190 Now, this service, quite commonly referred 58 00:03:12,190 --> 00:03:16,870 to as Ethernet over MPLS, can be implemented 59 00:03:16,870 --> 00:03:18,800 in two different ways. 60 00:03:18,800 --> 00:03:22,390 First is point-to-point, which is essentially what 61 00:03:22,390 --> 00:03:25,280 I drew up here as our example. 62 00:03:25,280 --> 00:03:30,740 The other option is multipoint, or Virtual Private LAN Service, 63 00:03:30,740 --> 00:03:32,530 VPLS. 64 00:03:32,530 --> 00:03:37,000 In this example, the customer has multiple routers. 65 00:03:37,000 --> 00:03:39,040 These are all going to be connected 66 00:03:39,040 --> 00:03:43,300 by the VPLS being offered by the service provider. 67 00:03:43,300 --> 00:03:48,340 And in turn, this ends up looking like an Ethernet switch 68 00:03:48,340 --> 00:03:49,940 to the customer. 69 00:03:49,940 --> 00:03:55,150 So for example, if, again, the customer was running OSPF, 70 00:03:55,150 --> 00:03:59,530 it would treat this as if you were running OSPF on Ethernet, 71 00:03:59,530 --> 00:04:03,500 and all of these routers would become neighbors. 72 00:04:03,500 --> 00:04:05,620 Now, this isn't really our discussion right now. 73 00:04:05,620 --> 00:04:08,240 But realistically, what would happen, of course, 74 00:04:08,240 --> 00:04:11,410 is one of these would become the DR. One of these 75 00:04:11,410 --> 00:04:13,730 would become a BDR. 76 00:04:13,730 --> 00:04:15,560 And we would become fully adjacent 77 00:04:15,560 --> 00:04:18,079 with the DR and the BDR. 78 00:04:18,079 --> 00:04:21,290 But we're not really talking about full neighborships 79 00:04:21,290 --> 00:04:22,580 here with OSPF. 80 00:04:22,580 --> 00:04:24,500 We're simply saying that they would 81 00:04:24,500 --> 00:04:26,330 be able to communicate with each other 82 00:04:26,330 --> 00:04:30,960 because they all see each other as being on the same segment. 83 00:04:30,960 --> 00:04:35,240 So next, let's focus on our Layer 3 VPNs. 84 00:04:35,240 --> 00:04:40,190 Layer 3 VPNs are quite commonly offered to act as a WAN service 85 00:04:40,190 --> 00:04:41,730 for the customer. 86 00:04:41,730 --> 00:04:44,570 But these are also used quite commonly 87 00:04:44,570 --> 00:04:47,790 in the core of enterprise networks. 88 00:04:47,790 --> 00:04:51,320 So this isn't just a service provider technology. 89 00:04:51,320 --> 00:04:54,990 We can use it in large enterprises as well. 90 00:04:54,990 --> 00:04:59,120 Now, the big difference here, of course, from Layer 2 VPN, 91 00:04:59,120 --> 00:05:03,920 is, here, the customer routes are actually learned 92 00:05:03,920 --> 00:05:06,380 from the Customer Edge routers. 93 00:05:06,380 --> 00:05:09,170 This is already implying that the routes 94 00:05:09,170 --> 00:05:13,710 are being learned by the service provider from the customer. 95 00:05:13,710 --> 00:05:16,933 Now, any protocol can be used. 96 00:05:16,933 --> 00:05:19,100 We're going to use this term very carefully, though. 97 00:05:19,100 --> 00:05:21,410 Any protocol. 98 00:05:21,410 --> 00:05:24,140 What we, of course, mean is any protocol 99 00:05:24,140 --> 00:05:27,440 that the service provider chooses to support. 100 00:05:27,440 --> 00:05:30,650 Technically, yes, we can support things 101 00:05:30,650 --> 00:05:35,510 like RIP version 1, RIP version 2, EIGRP. 102 00:05:35,510 --> 00:05:37,910 Those, however, are not very commonly 103 00:05:37,910 --> 00:05:41,630 supported by the service provider, just because-- 104 00:05:41,630 --> 00:05:43,130 well that means that we have to have 105 00:05:43,130 --> 00:05:46,220 technicians that understand those protocols, and so on. 106 00:05:46,220 --> 00:05:48,920 It's more overhead for us to support 107 00:05:48,920 --> 00:05:51,710 some legacy, or not-so-popular, maybe 108 00:05:51,710 --> 00:05:54,530 proprietary routing protocols. 109 00:05:54,530 --> 00:05:58,400 Quite commonly, the only one supported is BGP. 110 00:05:58,400 --> 00:06:00,590 That's getting more and more popular. 111 00:06:00,590 --> 00:06:04,950 I know some service providers do still offer OSPF as well. 112 00:06:04,950 --> 00:06:07,730 But OSPF and BGP are the only two 113 00:06:07,730 --> 00:06:11,000 I'm aware of that service providers are offering. 114 00:06:11,000 --> 00:06:14,450 There always might be some that offer additional ones. 115 00:06:14,450 --> 00:06:17,360 Now again, keep in mind, all of these protocols 116 00:06:17,360 --> 00:06:20,540 have their own caveats that the service provider 117 00:06:20,540 --> 00:06:21,540 would have to deal with. 118 00:06:21,540 --> 00:06:24,470 And that's part of why we don't really 119 00:06:24,470 --> 00:06:28,820 like to support these from the service provider's standpoint. 120 00:06:28,820 --> 00:06:33,770 BGP, of course, like I said, is the most common implementation 121 00:06:33,770 --> 00:06:34,890 here. 122 00:06:34,890 --> 00:06:37,250 And just another interesting point, 123 00:06:37,250 --> 00:06:39,920 this is all about what protocol the customer 124 00:06:39,920 --> 00:06:43,490 wants to run with the provider for the Layer 3 VPN. 125 00:06:43,490 --> 00:06:47,160 We usually call this the CE-PE routing protocol. 126 00:06:47,160 --> 00:06:51,470 Now, if the customer doesn't know BGP, 127 00:06:51,470 --> 00:06:54,350 which is quite commonly the pushback 128 00:06:54,350 --> 00:06:56,180 that you'll get from customers. 129 00:06:56,180 --> 00:06:58,100 Well, we're running OSPF. 130 00:06:58,100 --> 00:07:00,410 We want to run Layer 3 VPN with you. 131 00:07:00,410 --> 00:07:02,180 Can't we just run OSPF with you? 132 00:07:02,180 --> 00:07:06,230 We don't really have anybody on staff who knows BGP. 133 00:07:06,230 --> 00:07:09,320 This is actually an opportunity for a good upsell 134 00:07:09,320 --> 00:07:13,140 to try to get them to do managed edge services. 135 00:07:13,140 --> 00:07:15,620 We can simply say, oh, well, tell you what? 136 00:07:15,620 --> 00:07:20,750 We can run the CE for you, for a nominal monthly fee. 137 00:07:20,750 --> 00:07:23,760 And we can run the customer's router for them. 138 00:07:23,760 --> 00:07:26,840 And we'll take care of redistributing 139 00:07:26,840 --> 00:07:32,900 between the OSPF and the BGP, and do it on the CE router. 140 00:07:32,900 --> 00:07:35,060 And besides just the upsell here, 141 00:07:35,060 --> 00:07:39,320 it also allows us to scale our PE routers 142 00:07:39,320 --> 00:07:43,910 much better because it's less work on the PE router. 143 00:07:43,910 --> 00:07:46,430 Otherwise, if we support OSPF, not only 144 00:07:46,430 --> 00:07:48,410 do we have to run OSPF with the customer 145 00:07:48,410 --> 00:07:51,740 then, while we're still running BGP-- 146 00:07:51,740 --> 00:07:55,190 keep in mind, that means that that PE router is also 147 00:07:55,190 --> 00:07:57,570 going to have to do the redistribution as well. 148 00:07:57,570 --> 00:08:02,660 So it actually offloads a lot of work back to the customer 149 00:08:02,660 --> 00:08:04,910 if we insist that they actually run 150 00:08:04,910 --> 00:08:09,180 BGP, which is part of why it's a very popular choice. 151 00:08:09,180 --> 00:08:11,780 Now, of course, it's incredibly important, if we're 152 00:08:11,780 --> 00:08:15,170 going to be supporting multiple customers in this environment, 153 00:08:15,170 --> 00:08:18,290 that their routes are kept isolated. 154 00:08:18,290 --> 00:08:22,190 We cannot be mixing and matching traffic between our customers. 155 00:08:22,190 --> 00:08:24,380 They're not going to be very happy. 156 00:08:24,380 --> 00:08:26,270 Because again, this is supposed to be 157 00:08:26,270 --> 00:08:28,730 acting as their WAN service. 158 00:08:28,730 --> 00:08:30,770 If they wanted their traffic intermingled 159 00:08:30,770 --> 00:08:33,710 with everybody else's, they would just use the internet. 160 00:08:33,710 --> 00:08:38,370 This is supposed to be private circuits for the customer. 161 00:08:38,370 --> 00:08:41,730 Now, again, we're going to talk about this in much more detail. 162 00:08:41,730 --> 00:08:44,660 But just the short version is, on the PE, 163 00:08:44,660 --> 00:08:47,990 we're going to do this using VRFs, or Virtual Routers 164 00:08:47,990 --> 00:08:50,660 and Forwarders, in the core. 165 00:08:50,660 --> 00:08:55,290 This is exactly what these VPN labels are for. 166 00:08:55,290 --> 00:08:58,590 And that keeps the traffic isolated. 167 00:08:58,590 --> 00:09:01,680 And since they're isolated, it means the customers 168 00:09:01,680 --> 00:09:04,260 can use any addressing. 169 00:09:04,260 --> 00:09:06,810 And more importantly, it means they can 170 00:09:06,810 --> 00:09:09,570 use overlapping address space. 171 00:09:09,570 --> 00:09:12,780 The reason this is important is, keep in mind, once again, 172 00:09:12,780 --> 00:09:16,560 this is their WAN service, which means that it's inside 173 00:09:16,560 --> 00:09:21,720 of their network, most likely inside of their NAT engine, 174 00:09:21,720 --> 00:09:26,040 which means they're probably using private addressing. 175 00:09:26,040 --> 00:09:28,800 Well, how many companies out there do you think 176 00:09:28,800 --> 00:09:34,270 are all using RFC 1918 addresses inside their company? 177 00:09:34,270 --> 00:09:38,980 That's literally the point of RFC 1918 addresses. 178 00:09:38,980 --> 00:09:42,030 So do you have any idea how many enterprises are all using 179 00:09:42,030 --> 00:09:44,760 10 dot inside of their network? 180 00:09:44,760 --> 00:09:48,330 Or 172.16 to 172.31. 181 00:09:48,330 --> 00:09:51,090 Well, not too many probably use 192.168. 182 00:09:51,090 --> 00:09:54,420 Those are usually for home, or maybe small office use. 183 00:09:54,420 --> 00:09:58,600 But the point is, there's going to be a ton of overlap here. 184 00:09:58,600 --> 00:10:01,390 So we have to make sure that we can accommodate that. 185 00:10:01,390 --> 00:10:03,430 And by keeping it isolated-- 186 00:10:03,430 --> 00:10:05,310 which, again, we'll hit more detail 187 00:10:05,310 --> 00:10:07,830 on later-- but by keeping these isolated, 188 00:10:07,830 --> 00:10:09,645 we allow that to happen. 189 00:10:09,645 --> 00:10:11,520 Now, in case you've been looking at all this, 190 00:10:11,520 --> 00:10:14,610 wondering what the big advantage is of having the service 191 00:10:14,610 --> 00:10:16,800 provider involved in the routing, 192 00:10:16,800 --> 00:10:20,890 as opposed to the Layer 2 VPN we talked about a moment ago-- 193 00:10:20,890 --> 00:10:22,350 well, it's really here. 194 00:10:22,350 --> 00:10:27,420 It's that we can provide optimal traffic delivery because we 195 00:10:27,420 --> 00:10:29,520 know the customers routes. 196 00:10:29,520 --> 00:10:32,310 If we know the customer routes, we're 197 00:10:32,310 --> 00:10:35,670 effectively providing a full mesh 198 00:10:35,670 --> 00:10:38,040 of connectivity for that customer 199 00:10:38,040 --> 00:10:40,410 because we will deliver their traffic 200 00:10:40,410 --> 00:10:44,800 to the closest available site that has that destination. 201 00:10:44,800 --> 00:10:47,740 So this is very efficient. 202 00:10:47,740 --> 00:10:49,380 Now, this is one of those technologies 203 00:10:49,380 --> 00:10:52,080 that's going to use two labels. 204 00:10:52,080 --> 00:10:56,130 We're going to use an LDP-learned label, also known 205 00:10:56,130 --> 00:10:58,440 as the forwarding label, to forward 206 00:10:58,440 --> 00:11:01,740 that traffic to the egress PE. 207 00:11:01,740 --> 00:11:04,440 So this is going to be used to forward the traffic 208 00:11:04,440 --> 00:11:06,330 through the MPLS core. 209 00:11:06,330 --> 00:11:12,360 Then we have a multi-protocol BGP-learned label that's used 210 00:11:12,360 --> 00:11:15,720 to identify the egress VRF-- 211 00:11:15,720 --> 00:11:17,940 or route, or interface. 212 00:11:17,940 --> 00:11:22,640 But most likely, it's going to be the egress VRF. 213 00:11:22,640 --> 00:11:26,120 So in this video, we just got an introduction 214 00:11:26,120 --> 00:11:29,240 to our two major types of VPNs. 215 00:11:29,240 --> 00:11:31,470 That we can offer to our customers. 216 00:11:31,470 --> 00:11:35,030 We have our Layer 2 VPN, which, again, can either 217 00:11:35,030 --> 00:11:38,300 be point-to-point or multipoint, acting 218 00:11:38,300 --> 00:11:40,910 like just a single circuit for the customer, 219 00:11:40,910 --> 00:11:44,720 or essentially acting as an Ethernet switch. 220 00:11:44,720 --> 00:11:49,730 That environment is completely uninvolved with the customer 221 00:11:49,730 --> 00:11:50,550 routing. 222 00:11:50,550 --> 00:11:53,750 In other words, the customer's just getting a Layer 2 handoff. 223 00:11:53,750 --> 00:11:57,560 And from the perspective of things like routing protocols, 224 00:11:57,560 --> 00:11:59,240 they're going to think they're actually 225 00:11:59,240 --> 00:12:00,840 neighbors of each other. 226 00:12:00,840 --> 00:12:03,560 Then we have the Layer 3 VPN. 227 00:12:03,560 --> 00:12:07,010 The layer VPN, of course, the service provider 228 00:12:07,010 --> 00:12:08,390 learns the routes. 229 00:12:08,390 --> 00:12:10,430 And we're going to have to do things 230 00:12:10,430 --> 00:12:12,860 like keep those routes separate, because we 231 00:12:12,860 --> 00:12:15,440 can't be intermingling customer traffic 232 00:12:15,440 --> 00:12:17,510 between multiple customers. 233 00:12:17,510 --> 00:12:20,450 However, it has the advantage of being 234 00:12:20,450 --> 00:12:22,700 able to deliver the traffic to the best 235 00:12:22,700 --> 00:12:26,540 site for that destination, effectively 236 00:12:26,540 --> 00:12:30,140 making this act like an incredibly efficient full mesh 237 00:12:30,140 --> 00:12:31,590 connection. 238 00:12:31,590 --> 00:12:34,580 Now, this is only one of the advanced services 239 00:12:34,580 --> 00:12:36,860 that MPLS offers. 240 00:12:36,860 --> 00:12:39,230 Traffic Engineering is another one. 241 00:12:39,230 --> 00:12:42,050 And we're going to talk about that one from an introduction 242 00:12:42,050 --> 00:12:43,980 standpoint next. 243 00:12:43,980 --> 00:12:47,270 Until then, I hope this has been informative for you, 244 00:12:47,270 --> 00:12:50,380 and I'd like to thank you for viewing. 245 00:12:50,380 --> 00:12:54,000