WEBVTT 1 00:00.000 --> 00:04.560 All right, let's log into the lab and make sure we can configure UDLD and loop 2 00:04.560 --> 00:05.120 guard. 3 00:05.120 --> 00:08.770 We're basically going to be doing the same configurations that we did during 4 00:08.770 --> 00:09.440 the skill, 5 00:09.440 --> 00:12.570 but this is our opportunity to log in, make sure we know how to configure it 6 00:12.570 --> 00:13.040 and make 7 00:13.040 --> 00:15.440 sure we know how to verify that it's working. 8 00:15.440 --> 00:18.480 So task number one here says we're going to configure the link between switches 9 00:18.480 --> 00:18.800 three 10 00:18.800 --> 00:19.800 and four. 11 00:19.800 --> 00:22.040 That would be gig one slash zero here. 12 00:22.040 --> 00:29.240 I'm going to say config T interface gig one slash zero and we're told to 13 00:29.240 --> 00:30.640 protect ourselves WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 13 00:29.240 --> 00:30.640 protect ourselves 14 00:30.640 --> 00:32.160 from unidirectional communication. 15 00:32.160 --> 00:34.920 So I'd be UDLD and we have to assume the link is copper. 16 00:34.920 --> 00:39.500 Now remember global configuration applies only to fiber ports interface level 17 00:39.500 --> 00:40.480 configuration 18 00:40.480 --> 00:41.480 applies regardless. 19 00:41.480 --> 00:45.060 So if this is a copper port, I'm going to have to configure it on the interface 20 00:45.060 --> 00:45.160 . 21 00:45.160 --> 00:48.280 So we're in the right place interface gig one slash zero. 22 00:48.280 --> 00:52.240 And then we're also told to ensure the link gets placed into air disable. 23 00:52.240 --> 00:54.880 So I do UDLD port question mark. 24 00:54.880 --> 00:58.200 And remember, I can hit enter here for normal, but if I wanted to go into air 25 00:58.200 --> 00:58.840 disable, I 26 00:58.840 --> 01:02.280 have to configure aggressive mode. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 26 00:58.840 --> 01:02.280 have to configure aggressive mode. 27 01:02.280 --> 01:05.200 So I'm going to configure that for aggressive. 28 01:05.200 --> 01:09.070 And I do have to configure that on the other side, configure it on one side is 29 01:09.070 --> 01:09.680 not going 30 01:09.680 --> 01:10.680 to work. 31 01:10.680 --> 01:16.280 So interface gig one slash zero on this side, UDLD port aggressive. 32 01:16.280 --> 01:21.590 So now I should be able to run some of those UDLD commands such as show UDLD 33 01:21.590 --> 01:22.240 neighbor. 34 01:22.240 --> 01:25.120 And I can already see that I have my neighbor on the other side. 35 01:25.120 --> 01:27.920 Now it's an unknown state here because I ran it so fast. 36 01:27.920 --> 01:29.160 We should see that there we go. 37 01:29.160 --> 01:33.640 We're in bi directional now we are receiving our own echoed keep alive messages WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 37 01:29.160 --> 01:33.640 We're in bi directional now we are receiving our own echoed keep alive messages 38 01:33.640 --> 01:33.960 . 39 01:33.960 --> 01:34.960 Perfect. 40 01:34.960 --> 01:37.720 So task number two is talking about switch five here. 41 01:37.720 --> 01:41.020 Let's get over to switch five configure switch five to protect the network from 42 01:41.020 --> 01:41.160 an 43 01:41.160 --> 01:43.200 STP process failure. 44 01:43.200 --> 01:44.920 We're going to do exactly the same thing here. 45 01:44.920 --> 01:48.620 We want to make sure that the port that is currently in a blocking state so I 46 01:48.620 --> 01:49.120 could do 47 01:49.120 --> 01:53.330 show spanning tree blocked ports, find that that same interface is in a 48 01:53.330 --> 01:54.680 blocking state. 49 01:54.680 --> 01:58.740 And I want to make sure it stays in a blocking state if switch for stop sending 50 01:58.740 --> 01:59.480 BP to use. 51 01:59.480 --> 02:05.500 So simply put we want to configure a loop guard and we can just do that WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 51 01:59.480 --> 02:05.500 So simply put we want to configure a loop guard and we can just do that 52 02:05.500 --> 02:06.200 globally or we 53 02:06.200 --> 02:07.560 could do it on the interface. 54 02:07.560 --> 02:11.440 Let's just do it globally spanning tree loop guard. 55 02:11.440 --> 02:13.860 And then the command is default. 56 02:13.860 --> 02:16.360 And so from here we should see that's protected. 57 02:16.360 --> 02:19.870 Again, we can verify that show spanning tree interface tells us that 58 02:19.870 --> 02:21.000 information gig three 59 02:21.000 --> 02:23.040 slash one detail. 60 02:23.040 --> 02:26.160 And we do see that it is enabled by default on the port. 61 02:26.160 --> 02:32.070 Now I can go to switch for interface gig three slash one and say spanning tree WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 61 02:26.160 --> 02:32.070 Now I can go to switch for interface gig three slash one and say spanning tree 62 02:32.070 --> 02:32.720 BP to 63 02:32.720 --> 02:35.680 filter enable. 64 02:35.680 --> 02:38.840 And then all we have to do is wait our 20 seconds. 65 02:38.840 --> 02:44.210 And ideally we find that this does go into the STP inconsistent state with that 66 02:44.210 --> 02:44.820 broken 67 02:44.820 --> 02:45.820 status. 68 02:45.820 --> 02:50.510 Otherwise, otherwise we'll form the loop because we just disabled BP or yeah, 69 02:50.510 --> 02:51.220 BP to use getting 70 02:51.220 --> 02:53.220 sent by switch four. 71 02:53.220 --> 02:55.900 So we wait the max age timer here and there we go. 72 02:55.900 --> 02:58.060 Loop guard has indeed blocked that port. 73 02:58.060 --> 03:01.940 So these are two very critical configurations. WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 73 02:58.060 --> 03:01.940 So these are two very critical configurations. 74 03:01.940 --> 03:03.900 We mentioned this in the last video as well. 75 03:03.900 --> 03:06.460 Our last skill BP to you guard route guard. 76 03:06.460 --> 03:10.960 And now we're talking about loop guard and you do all four of these absolutely 77 03:10.960 --> 03:11.480 belong 78 03:11.480 --> 03:13.400 in our modern network configurations. 79 03:13.400 --> 03:15.200 They belong in production. 80 03:15.200 --> 03:18.400 We need to make sure we understand exactly how they work as well as where to 81 03:18.400 --> 03:19.060 deploy them 82 03:19.060 --> 03:23.330 in the network in order to protect our spanning tree topologies that we build 83 03:23.330 --> 03:24.140 and then also 84 03:24.140 --> 03:27.720 protect ourselves from loops that can indeed occur. 85 03:27.720 --> 03:28.880 And it's a real threat. 86 03:28.880 --> 03:31.580 It could actually occur in our environment if we don't have these WEBVTT X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:900000 86 03:28.880 --> 03:31.580 It could actually occur in our environment if we don't have these 87 03:31.580 --> 03:33.380 configurations in place. 88 03:33.380 --> 03:35.960 I hope this has been informative for you and I'd like to thank you for viewing.