1 00:00:02,288 --> 00:00:08,386 [music] 2 00:00:08,386 --> 00:00:13,742 We're going to start talking now about some of our transition mechanisms. 3 00:00:13,816 --> 00:00:18,486 Specifically, we're going to talk about tunnels, and we're going to 4 00:00:18,486 --> 00:00:24,154 talk about just running dual stack, which is a fairly short conversation, 5 00:00:24,154 --> 00:00:25,952 but we'll wrap up with that. 6 00:00:25,952 --> 00:00:30,352 Tunnels, though, we have quite a few different choices 7 00:00:30,352 --> 00:00:31,989 that we're going to go through. 8 00:00:31,989 --> 00:00:36,036 Choice number one is just a standard GRE, 9 00:00:36,036 --> 00:00:43,544 Generic Routing Encapsulation tunnel, and we can run IPv4 over IPv4, 10 00:00:43,544 --> 00:00:46,036 IPv6 over IPv4. 11 00:00:46,036 --> 00:00:48,447 That's, of course, the one we're going to be looking at, 12 00:00:48,447 --> 00:00:55,044 is a way to get IPv6 transported through an IPv4-only network 13 00:00:55,044 --> 00:00:57,378 inside of a GRE tunnel. 14 00:00:57,378 --> 00:01:01,782 Very simple, very straightforward. That will actually probably be 15 00:01:01,782 --> 00:01:03,789 a very, very short lesson. 16 00:01:05,119 --> 00:01:08,158 Then we have IPv6 IP tunnels. 17 00:01:08,158 --> 00:01:12,204 This is a very, very short, again, transition. 18 00:01:12,204 --> 00:01:18,245 I'll probably do these two in one lesson actually, GRE and IPv6 IP, 19 00:01:18,245 --> 00:01:22,714 just the generic IPv6 IP tunnels. 20 00:01:23,110 --> 00:01:30,787 And then from there we're going to move into some of the other IPv6. 21 00:01:30,787 --> 00:01:37,266 And understand, IPv6 IP also includes 6 to 4 tunnels. 22 00:01:38,733 --> 00:01:42,100 That is a type of IPv6 IP tunnel. 23 00:01:42,100 --> 00:01:47,695 So now we're starting to get into some specifics under IPv6 IP tunnel types. 24 00:01:47,946 --> 00:01:51,502 As we're going down here, basically what we're saying is, Okay, 25 00:01:51,502 --> 00:01:55,184 you've got GRE, which means you're going to have the IPv4 header, 26 00:01:55,184 --> 00:02:01,008 followed by a GRE header, followed by an IPv6 header on the inside. 27 00:02:01,353 --> 00:02:06,923 And because we have a GRE header, the GRE header has a type field in it. 28 00:02:06,923 --> 00:02:11,356 That allows us to run IPv4 and IPv6. 29 00:02:11,356 --> 00:02:16,460 And, I guess, if you still cared, IPX/SPX, or DECnet or something over 30 00:02:16,460 --> 00:02:19,793 that same tunnel, if your code even still support that stuff. 31 00:02:19,910 --> 00:02:25,968 But the point is, we can run multiple protocols over the same tunnel. 32 00:02:26,144 --> 00:02:32,562 When you go to IPv6 IP tunnel, you are simply eliminating the GRE header. 33 00:02:32,714 --> 00:02:35,983 And just in the interest of looking at MTU and all that kind of 34 00:02:35,983 --> 00:02:38,581 stuff, I think we will still separate those out. 35 00:02:38,715 --> 00:02:43,584 But, the point is, all we're really doing is eliminating the GRE header 36 00:02:43,584 --> 00:02:45,520 by saying, You know what? 37 00:02:45,520 --> 00:02:49,502 The only thing I'm going to run over this tunnel is IPv6. 38 00:02:49,664 --> 00:02:53,764 So why do I need another header to tell me what the next protocol 39 00:02:53,764 --> 00:02:59,634 is if I just tell both sides, Hey, the next protocol, 40 00:02:59,634 --> 00:03:02,937 the Layer 3 protocol here is IPv6. 41 00:03:03,085 --> 00:03:05,975 I don't need GRE to tell me it's IPv6, 42 00:03:05,975 --> 00:03:10,411 I'm going to program you to know that it's IPv6. 43 00:03:11,180 --> 00:03:16,918 Now, the problem with GRE and IPv6 IP by itself, 44 00:03:16,918 --> 00:03:21,603 is those are both static point-to-point tunnels. 45 00:03:21,967 --> 00:03:30,844 That's great, right up until you have 200 remote sites, 400, 1000, whatever. 46 00:03:30,844 --> 00:03:38,572 It gets quite a bit tedious if you have too many remote sites. 47 00:03:38,572 --> 00:03:41,780 So as we move into 6 to 4, the idea was, 48 00:03:41,780 --> 00:03:45,412 well, here's a way to dynamically build the tunnels. 49 00:03:45,616 --> 00:03:49,758 So these are going to be dynamic multipoint tunnels. 50 00:03:50,829 --> 00:03:54,556 And then you also have ISATAP, which is the same thing - 51 00:03:54,556 --> 00:03:56,637 dynamic multipoint tunnels. 52 00:03:56,637 --> 00:03:58,795 Little easier to configure. 53 00:03:59,766 --> 00:04:03,902 I don't know, I like to refer to them as the progression from 6 to 4. 54 00:04:03,902 --> 00:04:06,103 I'm not sure if that's technically accurate or not, 55 00:04:06,103 --> 00:04:10,471 but they're certainly easier to configure, that's for certain. 56 00:04:10,660 --> 00:04:14,913 And then we'll get into MPLS. 57 00:04:15,067 --> 00:04:20,043 Now, MPLS is just another way of transporting 58 00:04:20,055 --> 00:04:23,959 packets without doing IP forwarding. 59 00:04:24,202 --> 00:04:29,489 So, this is again going to be an IPv4 core with IPv6 running over 60 00:04:29,489 --> 00:04:33,732 top of it, and we'll look at that from two different perspectives. 61 00:04:33,732 --> 00:04:39,380 We'll look at it from 6 PE, which would be more of an enterprise-type 62 00:04:39,380 --> 00:04:45,881 solution, and then we'll look at it from a 6 VPE, which could also 63 00:04:45,881 --> 00:04:48,576 be enterprise, it depends on how you're running your network, 64 00:04:48,576 --> 00:04:53,383 but definitely what the service provider would be doing. 65 00:04:53,857 --> 00:04:57,593 The service provider's not going to do 6 PE, because that does not 66 00:04:57,593 --> 00:04:59,154 support multiple customer. 67 00:04:59,154 --> 00:05:03,002 That would just be, like I said, one enterprise doing this in your core. 68 00:05:03,296 --> 00:05:09,771 So that's another way to get 6 through another protocol, like IPv4. 69 00:05:09,771 --> 00:05:14,436 In this case, instead of using GRE and tunnel encapsulation, 70 00:05:14,436 --> 00:05:17,678 using MPLS for our transport. 71 00:05:17,887 --> 00:05:24,684 And last but not least, we will look at GRE multipoint, which is, of course, DMVPN. 72 00:05:25,026 --> 00:05:29,588 So we'll be taking a look at each one of these types of tunnels 73 00:05:29,588 --> 00:05:32,595 one at a time as we go through. 74 00:05:32,595 --> 00:05:36,990 [music]