WEBVTT 1 00:00.000 --> 00:04.400 All right, let's go ahead and answer some questions about software defined 2 00:04.400 --> 00:05.200 accesses or 3 00:05.200 --> 00:09.180 relates back to these overlay technologies we've been talking about, especially 4 00:09.180 --> 00:09.480 LISP 5 00:09.480 --> 00:11.040 and VXLAN. 6 00:11.040 --> 00:15.530 So again, SDA is going to run using these protocols and we're trying to build 7 00:15.530 --> 00:16.600 something a little 8 00:16.600 --> 00:20.480 bit better than just straight up layer two to the access layer or layer three 9 00:20.480 --> 00:20.880 to the 10 00:20.880 --> 00:22.040 access layer. 11 00:22.040 --> 00:25.980 Keep in mind when we see an SDA fabric topology like this, these are going to 12 00:25.980 --> 00:26.920 be access layer 13 00:26.920 --> 00:27.920 switches. 14 00:27.920 --> 00:32.060 There are switches that exist inside our access closets, inside our networks, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 14 00:27.920 --> 00:32.060 There are switches that exist inside our access closets, inside our networks, 15 00:32.060 --> 00:32.320 and then we 16 00:32.320 --> 00:36.870 have real hosts, real people, real, well, maybe the people don't connect to the 17 00:36.870 --> 00:37.640 network, 18 00:37.640 --> 00:41.950 but they're laptops, they're desktops, printers, access points, all of these 19 00:41.950 --> 00:42.720 access layer 20 00:42.720 --> 00:46.220 devices, phones, by the way, if we have voice over IP phones, all of these 21 00:46.220 --> 00:47.240 would be connecting 22 00:47.240 --> 00:49.520 in via these switches. 23 00:49.520 --> 00:52.870 So question number one here, what type of network exists between switch one and 24 00:52.870 --> 00:53.200 switch 25 00:53.200 --> 00:54.200 two? 26 00:54.200 --> 00:55.480 What is going on in here? 27 00:55.480 --> 00:58.080 Well, this is a layer three network. 28 00:58.080 --> 01:02.840 All of these are going to be layer three endpoints, so we are routing in this WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 28 00:58.080 --> 01:02.840 All of these are going to be layer three endpoints, so we are routing in this 29 01:02.840 --> 01:03.600 domain. 30 01:03.600 --> 01:09.220 We can run a routing protocol like OSPF or EIGRP, but either way, we are 31 01:09.220 --> 01:10.120 scaling out 32 01:10.120 --> 01:14.070 at layer three here, and regardless of how many edge switches we have, they're 33 01:14.070 --> 01:14.520 all going 34 01:14.520 --> 01:17.080 to connect to one another at layer three. 35 01:17.080 --> 01:20.600 So what type of tunnel is built between switch one and switch two? 36 01:20.600 --> 01:25.560 Well, at this point, we know that we are building a VXLAN tunnel. 37 01:25.560 --> 01:29.780 We're not deploying a LISP tunnel because LISP tunnels are layer three, but we 38 01:29.780 --> 01:30.360 are going WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 38 01:29.780 --> 01:30.360 are going 39 01:30.360 --> 01:36.440 to instead use VXLAN to form layer two over layer three using these tunnels. 40 01:36.440 --> 01:39.950 It's a wonderful technology, came out of the data centers we talked about, and 41 01:39.950 --> 01:40.320 now we're 42 01:40.320 --> 01:42.880 using it for SD access. 43 01:42.880 --> 01:47.560 So next, if switch one doesn't know where host B lives, what will it do? 44 01:47.560 --> 01:50.320 Well, this is where LISP starts to get involved. 45 01:50.320 --> 01:53.870 If we didn't have a control plane protocol, we would just have to flood it out 46 01:53.870 --> 01:54.360 not only 47 01:54.360 --> 01:58.780 to switch two, but potentially to all kinds of other switches until we learned 48 01:58.780 --> 01:59.480 where host 49 01:59.480 --> 02:00.560 B lived. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 49 01:59.480 --> 02:00.560 B lived. 50 02:00.560 --> 02:02.400 Instead, we don't have to worry about that. 51 02:02.400 --> 02:07.720 I can use LISP to go to the control plane node. 52 02:07.720 --> 02:13.120 The control plane node is going to keep track of all of these hosts. 53 02:13.120 --> 02:18.720 And remember, from a LISP perspective, that's the responsibility of the MSMR. 54 02:18.720 --> 02:22.680 Now we're not going to use LISP terms with software defined access. 55 02:22.680 --> 02:26.400 Instead, we are going to call this a control plane node. 56 02:26.400 --> 02:30.670 So I'm going to go to the control plane node and I'm going to pull down the WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 56 02:26.400 --> 02:30.670 So I'm going to go to the control plane node and I'm going to pull down the 57 02:30.670 --> 02:31.560 information. 58 02:31.560 --> 02:34.800 So now I know where host B lives. 59 02:34.800 --> 02:37.760 Host B is connected to switch two. 60 02:37.760 --> 02:41.690 And so I'm going to send it out the VXLAN tunnel that is built that I have 61 02:41.690 --> 02:42.440 built with 62 02:42.440 --> 02:45.320 switch two. 63 02:45.320 --> 02:49.340 Now again, if it does already have this information, so when the next packet 64 02:49.340 --> 02:50.400 arrives, I don't 65 02:50.400 --> 02:52.080 have to worry about this process. 66 02:52.080 --> 02:53.840 I don't have to go through this twice. 67 02:53.840 --> 02:58.040 I will eventually have, I mean, I'm putting this information into a cache. 68 02:58.040 --> 03:02.720 I will eventually time that cache out that entry and I will drop that. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 68 02:58.040 --> 03:02.720 I will eventually time that cache out that entry and I will drop that. 69 03:02.720 --> 03:06.020 But if the entry is still in my cache and I receive another packet, first of 70 03:06.020 --> 03:06.400 all, I'm 71 03:06.400 --> 03:11.800 going to refresh the cache timer, make sure I don't expire data that's actively 72 03:11.800 --> 03:12.200 being 73 03:12.200 --> 03:13.200 used. 74 03:13.200 --> 03:16.280 And I'm just going to send it straight into the VXLAN tunnel. 75 03:16.280 --> 03:21.030 And so this control plane mechanism of LISP is going to work wonderfully with V 76 03:21.030 --> 03:21.520 XLAN in 77 03:21.520 --> 03:24.120 order to enable our campus fabric. 78 03:24.120 --> 03:27.170 Just keep in mind in all of this that LISP works for the control plane and VX 79 03:27.170 --> 03:27.640 LAN works 80 03:27.640 --> 03:28.640 for the data plane. 81 03:28.640 --> 03:34.160 But we do still have that policy plane that's managed by ICE and especially WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 81 03:28.640 --> 03:34.160 But we do still have that policy plane that's managed by ICE and especially 82 03:34.160 --> 03:35.640 Cisco trussec. 83 03:35.640 --> 03:38.080 So this is how all of these protocols come together. 84 03:38.080 --> 03:43.120 And again, why Cisco really wants us to understand how LISP and VXLAN operate. 85 03:43.120 --> 03:47.450 We are expected to understand how exactly they operate independent of software 86 03:47.450 --> 03:47.960 defined 87 03:47.960 --> 03:48.960 access. 88 03:48.960 --> 03:51.480 But I really wanted to bring this back together at the end to say, okay, now 89 03:51.480 --> 03:52.160 that we know how 90 03:52.160 --> 03:54.000 they work, why do we care? 91 03:54.000 --> 03:55.720 We have to understand why we care. 92 03:55.720 --> 03:59.360 And at the end of the day, we care because Cisco is deploying these 93 03:59.360 --> 04:00.760 technologies actively WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 93 03:59.360 --> 04:00.760 technologies actively 94 04:00.760 --> 04:02.680 in software defined access. 95 04:02.680 --> 04:05.320 I hope this has been informative for you and I'd like to thank you for viewing.