WEBVTT 1 00:00.000 --> 00:05.040 Access Clause at Design used to be very challenging because we'd have a bunch 2 00:05.040 --> 00:06.260 of independent 3 00:06.260 --> 00:07.660 access switches. 4 00:07.660 --> 00:09.820 We'd have to create some kind of redundancy here. 5 00:09.820 --> 00:12.620 We'd have to make sure that we're connected upstream. 6 00:12.620 --> 00:14.980 Maybe we'd connect it like it's in the diagram. 7 00:14.980 --> 00:19.390 Maybe we'd try to create a loop through like this, but either way, again, we 8 00:19.390 --> 00:19.940 have a lot 9 00:19.940 --> 00:25.310 of challenges when the access switches are individual switches from one another 10 00:25.310 --> 00:25.380 . 11 00:25.380 --> 00:30.220 So we're asked to deploy technology that is going to kind of make things more WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 11 00:25.380 --> 00:30.220 So we're asked to deploy technology that is going to kind of make things more 12 00:30.220 --> 00:31.000 efficient 13 00:31.000 --> 00:32.320 for us. 14 00:32.320 --> 00:36.460 And so it starts by simplifying this access layer design, and we want to 15 00:36.460 --> 00:37.440 leverage chassis 16 00:37.440 --> 00:39.620 or stat switches. 17 00:39.620 --> 00:45.480 So what this allows us to do is essentially combine all of these together into 18 00:45.480 --> 00:46.200 a single 19 00:46.200 --> 00:50.100 logical switch. 20 00:50.100 --> 00:54.860 Now that could be either a chassis or a set of stackable switches. 21 00:54.860 --> 00:57.180 Lot of network engineers have their preference. 22 00:57.180 --> 00:59.180 Maybe you prefer one over the other. 23 00:59.180 --> 01:01.580 Maybe you say, "Yeah, they're all the same to me. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 23 00:59.180 --> 01:01.580 Maybe you say, "Yeah, they're all the same to me. 24 01:01.580 --> 01:03.000 It doesn't really matter." 25 01:03.000 --> 01:06.340 But either way, we would expect this now to be a single switch. 26 01:06.340 --> 01:10.360 So we can get rid of this connection or call it maybe the stack cable now, 27 01:10.360 --> 01:11.180 whatever it 28 01:11.180 --> 01:15.300 is, but either way, it doesn't show up on our network topology diagram. 29 01:15.300 --> 01:19.220 Now at this point, we still have STP blocking in place. 30 01:19.220 --> 01:23.820 And so next, we're asked to simplify the distribution block with a technology. 31 01:23.820 --> 01:28.750 Well, unfortunately, our network designs don't really promote turning this into 32 01:28.750 --> 01:30.220 a stack, WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 32 01:28.750 --> 01:30.220 a stack, 33 01:30.220 --> 01:31.460 like one big stack. 34 01:31.460 --> 01:33.540 We can't just say, "We don't need the second one. 35 01:33.540 --> 01:35.460 We'll just create a stack." 36 01:35.460 --> 01:39.950 And then we're good because if there's a control plane failure here or just 37 01:39.950 --> 01:40.700 flat out the 38 01:40.700 --> 01:44.620 whole switch reloads unintentionally or maybe even intentionally for 39 01:44.620 --> 01:45.980 maintenance, it would 40 01:45.980 --> 01:47.820 take down our entire distribution block. 41 01:47.820 --> 01:53.220 We don't want to put all of the proverbial eggs in one basket. 42 01:53.220 --> 01:59.020 So instead, what we do is we maintain two distinct logical switches. 43 01:59.020 --> 02:04.310 But what we can do is we can combine, I said that wrong, two distinct physical WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 43 01:59.020 --> 02:04.310 But what we can do is we can combine, I said that wrong, two distinct physical 44 02:04.310 --> 02:05.220 switches, 45 02:05.220 --> 02:08.220 but we combine them into one logical switch still. 46 02:08.220 --> 02:12.910 And so by combining them into one logical switch, by having two distinct 47 02:12.910 --> 02:14.220 physical switches, 48 02:14.220 --> 02:17.980 this allows us to hopefully simplify the architecture. 49 02:17.980 --> 02:20.100 Now what technology do we use to do this? 50 02:20.100 --> 02:24.780 Well, it used to be known as VSS technology virtual switching system. 51 02:24.780 --> 02:31.060 This would be on the old 6,500s and actually 6,800s and 4,500s as well. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 51 02:24.780 --> 02:31.060 This would be on the old 6,500s and actually 6,800s and 4,500s as well. 52 02:31.060 --> 02:36.460 But these days, on the nine case, we're going to call this stackwise virtual. 53 02:36.460 --> 02:42.670 Same concept, we're going to combine two physical switches into one logical 54 02:42.670 --> 02:43.620 switch. 55 02:43.620 --> 02:47.060 So now we have one logical switch at the distribution layer. 56 02:47.060 --> 02:51.300 We have one logical switch down here at the access layer. 57 02:51.300 --> 02:57.330 And if we have one logical switch in both locations, we can now port channel 58 02:57.330 --> 02:59.060 these two together, 59 02:59.060 --> 03:03.900 which eliminates the third, the spanning tree protocol blocking, which is what WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 59 02:59.060 --> 03:03.900 which eliminates the third, the spanning tree protocol blocking, which is what 60 03:03.900 --> 03:04.420 the third 61 03:04.420 --> 03:06.900 bullet point is asking us to do. 62 03:06.900 --> 03:11.710 So I will say this is the beautiful architecture that we would love to deploy 63 03:11.710 --> 03:12.700 to every single 64 03:12.700 --> 03:18.240 access closet, if possible, so that our distribution switches operate in this 65 03:18.240 --> 03:19.140 fashion. 66 03:19.140 --> 03:21.260 But unfortunately, there are limitations. 67 03:21.260 --> 03:25.300 For example, if there's a second switch down in the access closet, or if there 68 03:25.300 --> 03:25.980 are access 69 03:25.980 --> 03:30.890 closets that maybe we just have budgetary concerns or we have concerns around WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 69 03:25.980 --> 03:30.890 closets that maybe we just have budgetary concerns or we have concerns around 70 03:30.890 --> 03:31.660 stackwise 71 03:31.660 --> 03:36.220 virtual, whatever the situation is, there will be limitations to this. 72 03:36.220 --> 03:40.860 But if we can achieve this in our campus designs, it's going to greatly 73 03:40.860 --> 03:42.380 simplify our topologies 74 03:42.380 --> 03:44.620 from a spanning tree perspective. 75 03:44.620 --> 03:47.810 And it's going to reduce the amount of broadcast storms and just general 76 03:47.810 --> 03:48.780 network issues that 77 03:48.780 --> 03:49.180 we have. 78 03:49.180 --> 03:59.180 [BLANK_AUDIO]