1 00:00:00,840 --> 00:00:03,730 At the moment in this typology switch to the root. 2 00:00:04,170 --> 00:00:10,650 And we can prove that by using show spending tree and notice the local switches the route for the land 3 00:00:10,650 --> 00:00:20,530 one in the typology No the villains are being enabled so the only eaten at Villani existing at the moment 4 00:00:20,590 --> 00:00:25,560 is villaine one and all portside villaine one on all the switches. 5 00:00:25,870 --> 00:00:32,990 When looking at the BPT use we can see that the switch is advertising a route part cost of zero and 6 00:00:32,990 --> 00:00:41,690 the bridge ID and router identifier are the same on switch one when we capture traffic here. 7 00:00:44,880 --> 00:00:52,430 It's advertising a route path cost of four and you can see that the bridge identify is different to 8 00:00:52,430 --> 00:00:54,300 the route identifier. 9 00:00:54,820 --> 00:01:03,260 So on switch one let's change the spanning tree villaine one route. 10 00:01:03,380 --> 00:01:06,440 So change the switch to become the route. 11 00:01:07,010 --> 00:01:12,420 And in this case it will be the primary route that will drop the priority of the switch. 12 00:01:12,560 --> 00:01:19,170 Previously the switch was using a default priority which we can see in the Why Shock capture. 13 00:01:19,430 --> 00:01:28,380 It was 3 2 7 6 8 plus the villain number that now shows spending three shows us that the switch priority 14 00:01:28,380 --> 00:01:34,280 has been reduced to a value lower than any current route to bridge. 15 00:01:34,320 --> 00:01:40,200 So the switch has now become the route of the spending tree topology bridge MAC address and route MAC 16 00:01:40,200 --> 00:01:42,150 addresses the same. 17 00:01:42,150 --> 00:01:44,130 So there's our first wide shot capture. 18 00:01:44,370 --> 00:01:51,640 And if I scroll down to the latest advertisements notice the route part cost is 0. 19 00:01:51,810 --> 00:01:55,860 Preach ID and root identifier are the same. 20 00:01:55,860 --> 00:02:03,560 The properties have been reduced so this switch is the route with a lower priority. 21 00:02:03,640 --> 00:02:12,430 You can see that the bridge proteins 2 4 5 7 6 extended system IDs one because this is veel and 1 and 22 00:02:12,430 --> 00:02:15,520 the MAC address of the switch is set to the following. 23 00:02:16,230 --> 00:02:24,240 So once again if you look through the y shall capture the capture 114 at the moment previously the route 24 00:02:24,240 --> 00:02:27,900 identifier and bridge identify would different. 25 00:02:27,900 --> 00:02:32,520 Now what about switch to previously the switch was the route. 26 00:02:32,520 --> 00:02:39,290 So notice on capture one the switch previously had a route path cost of 0. 27 00:02:39,810 --> 00:02:47,760 But scrolling down to the captures you can now see that it has a route path Costa for it's a local bridge 28 00:02:47,790 --> 00:02:52,000 identifier has a higher priority. 29 00:02:52,130 --> 00:02:55,950 So the switch is no longer the spanning tree route. 30 00:02:56,030 --> 00:02:59,180 Previously on switch three this was the route port. 31 00:02:59,300 --> 00:03:05,560 So he has the output you can see that gigabit 0 0 was the route port on switch 3. 32 00:03:05,750 --> 00:03:07,060 What is it now. 33 00:03:07,100 --> 00:03:13,340 So show spanning tree notice gigabit 0 1 is the route port at the moment. 34 00:03:14,580 --> 00:03:21,400 So previously on switch 3 this was the route port but the route port has now changed to this port because 35 00:03:21,790 --> 00:03:22,360 the switches. 36 00:03:22,360 --> 00:03:29,110 Now the spending tree route the path cost using this link is four ways now the path cost using this 37 00:03:29,110 --> 00:03:31,210 link would be for plus fall. 38 00:03:31,210 --> 00:03:33,600 In other words 8 to get to the root bridge 39 00:03:36,440 --> 00:03:39,380 spanning tree typologies can done chemically change. 40 00:03:39,470 --> 00:03:51,160 So as an example if on switch three are shut down gigabit to 0 1 and top to show spending tree what 41 00:03:51,160 --> 00:03:57,560 we can see now is that gigabit is 0 0 is now the root port as this port is no longer available. 42 00:03:59,290 --> 00:04:01,960 If I know shut that interface 43 00:04:05,660 --> 00:04:13,550 and talk shows spending tree can see the interfaces Coming up what you can see now is that gigabit 0 44 00:04:13,550 --> 00:04:20,800 1 has become the root port once again whereas this port is now blocking to stop a spanning tree loop.