1 00:00:00,890 --> 00:00:05,900 To set up communication between switch one and switch to this port needs to be configured as a trunk 2 00:00:05,900 --> 00:00:06,470 port. 3 00:00:07,100 --> 00:00:13,340 I'm also going to configure these ports as trunk ports so that we can capture traffic and see the encapsulated 4 00:00:13,340 --> 00:00:16,970 frames between the switches, starting with switch one. 5 00:00:17,120 --> 00:00:20,930 The first thing I'm going to do is make everything static. 6 00:00:21,320 --> 00:00:28,530 So switch port mode access on gigabit zero zero and then switch port. 7 00:00:28,550 --> 00:00:28,790 No. 8 00:00:28,790 --> 00:00:31,690 Negotiate to disable DTP. 9 00:00:32,270 --> 00:00:39,350 Do something similar on gigabit is zero one switch port mode access switch port. 10 00:00:39,380 --> 00:00:39,800 No. 11 00:00:39,800 --> 00:00:40,670 Negotiate. 12 00:00:41,300 --> 00:00:41,810 Do show. 13 00:00:41,810 --> 00:00:42,380 Run. 14 00:00:45,870 --> 00:00:51,870 So this port zero zero is configured as an access port in VLAN one. 15 00:00:52,640 --> 00:00:54,170 DTP is disabled. 16 00:00:54,980 --> 00:00:55,480 Gigabit. 17 00:00:55,580 --> 00:01:01,700 Zero one is configured as an access port and VLAN two http is disabled. 18 00:01:03,740 --> 00:01:08,360 So we now need to configure ports two and three as trunk ports and disabled http. 19 00:01:08,660 --> 00:01:12,770 So interface gigabit is zero to switch port mode trunk. 20 00:01:12,980 --> 00:01:19,700 And it's going to fail, as you can see there, because we have to tap switch port trunk encapsulation 21 00:01:19,880 --> 00:01:28,310 and in this example we'll use dot one Q and then switch port mode trunk to make it a trunk port. 22 00:01:28,790 --> 00:01:35,300 A trunk port allows multiple VLANs to traverse that port switch port. 23 00:01:35,330 --> 00:01:36,560 No, negotiate. 24 00:01:37,100 --> 00:01:38,630 Let's do something similar. 25 00:01:39,810 --> 00:01:45,870 On Porch three set the encapsulation to dot one Q set the mode to trunk. 26 00:01:47,140 --> 00:01:51,520 Disable DTP and then I'll not shut those two ports. 27 00:01:53,050 --> 00:01:55,390 So show. 28 00:01:56,220 --> 00:01:57,270 Interface. 29 00:01:59,270 --> 00:02:01,820 Gigabit a zero to switch port. 30 00:02:03,020 --> 00:02:08,690 This command shows us that gigabit zero two is enabled as a Layer two interface. 31 00:02:08,870 --> 00:02:13,400 It's been administratively configured as a trunk and it's operating as a trunk. 32 00:02:13,520 --> 00:02:16,820 The encapsulation used is dot one Q. 33 00:02:16,910 --> 00:02:19,850 That's how it was configured and that's how it's operating. 34 00:02:20,180 --> 00:02:21,920 DTP has been disabled. 35 00:02:22,250 --> 00:02:28,700 The native VLAN or untagged VLAN on this link is VLAN one. 36 00:02:30,100 --> 00:02:33,310 All VLANs are allowed across the trunk. 37 00:02:33,700 --> 00:02:40,540 Now, we can also use the command show interface trunk that shows us a nice summary of information. 38 00:02:40,540 --> 00:02:46,480 So Port two and Port three have been manually configured for trunking using editor one. 39 00:02:46,480 --> 00:02:48,940 Q They are currently trunking. 40 00:02:48,940 --> 00:02:50,830 The native VLAN is VLAN one. 41 00:02:51,250 --> 00:02:55,960 VLANs 1 to 4094 are permitted on those ports. 42 00:02:56,650 --> 00:02:59,800 The VLANs allowed and active in the management domain of islands. 43 00:02:59,800 --> 00:03:07,150 1 to 2 VLANs in the spanning tree forwarding state on gigabit zero two is one and two and on three is 44 00:03:07,150 --> 00:03:07,750 two. 45 00:03:08,400 --> 00:03:13,230 So we've configured switch one with these ports being access ports. 46 00:03:14,130 --> 00:03:18,150 Currently this PC is in VLAN two. 47 00:03:20,890 --> 00:03:24,790 And this PC is in VLAN one. 48 00:03:25,360 --> 00:03:33,290 Now can router one, ping router two and router three and can router two ping any of those routers so 49 00:03:33,290 --> 00:03:36,640 it can write a one turn off debugging here. 50 00:03:36,970 --> 00:03:39,190 Ping ten 113. 51 00:03:40,420 --> 00:03:41,470 Yes, it can. 52 00:03:42,340 --> 00:03:44,680 Can it ping ten 114. 53 00:03:44,740 --> 00:03:45,850 Yes, it can. 54 00:03:46,420 --> 00:03:51,190 This port allows vlan one to traverse it using the untagged vlan. 55 00:03:51,490 --> 00:03:58,720 So the frame goes across this link as an untagged frame goes across this link as an untagged frame and 56 00:03:58,720 --> 00:04:01,270 then goes across these two links as untagged. 57 00:04:01,630 --> 00:04:04,420 Switch two hasn't been configured for VLANs. 58 00:04:04,450 --> 00:04:10,810 It's using a default config, so show vlan brief on the switch. 59 00:04:11,170 --> 00:04:14,770 Shows that only VLAN one exists on switch two. 60 00:04:15,220 --> 00:04:24,430 So let's put PC four into VLAN two and let's see if PC four and PC two can ping each other. 61 00:04:25,480 --> 00:04:29,980 Turn off debugging on router two acting as our PC show IP interface brief. 62 00:04:30,640 --> 00:04:37,960 This PC has an IP address of 10.1 to 2.2, so I'll give this one an IP address of 10.1 to 2.4. 63 00:04:40,120 --> 00:04:42,190 It's currently configured with this IP address. 64 00:04:42,190 --> 00:04:43,630 So let's change that. 65 00:04:45,610 --> 00:04:47,410 10.1 or 2.4. 66 00:04:50,300 --> 00:04:52,730 Paying 10.1 or 2.2. 67 00:04:53,540 --> 00:04:55,520 What you'll notice is the pings fail. 68 00:04:57,110 --> 00:04:59,630 Rather to and rather for cannot ping each other. 69 00:04:59,810 --> 00:05:01,580 And the question is why? 70 00:05:01,940 --> 00:05:04,690 Why can they not ping one another? 71 00:05:06,360 --> 00:05:13,170 Well, the first problem is we haven't configured VLAN two on the switch switch two and we haven't put 72 00:05:13,170 --> 00:05:14,910 this port into VLAN two. 73 00:05:15,300 --> 00:05:22,890 So on switch two, I'm going to set it to STP mode transparent so that we have to manually configure 74 00:05:22,890 --> 00:05:23,580 everything. 75 00:05:24,570 --> 00:05:30,420 I'm going to create VLAN two, but notice please, even though you create the VLAN, no ports are put 76 00:05:30,420 --> 00:05:32,110 into that VLAN by default. 77 00:05:32,130 --> 00:05:36,750 So show interface gigabit is zero one switch port. 78 00:05:37,020 --> 00:05:39,020 That's the interface here. 79 00:05:39,810 --> 00:05:42,540 Shows me that that port is in VLAN one. 80 00:05:43,380 --> 00:05:48,600 So what I need to do is go onto that port switchboard mode access. 81 00:05:49,370 --> 00:05:56,960 To ensure that it's an access port that is the default switch port access VLAN to switch port no negotiate 82 00:05:57,630 --> 00:06:03,440 to turn off all auto negotiations so that we have to manually configure everything and then explain 83 00:06:03,440 --> 00:06:04,190 how it works. 84 00:06:04,190 --> 00:06:08,420 So show interface gigabit zero one switch port. 85 00:06:09,600 --> 00:06:10,470 The support. 86 00:06:11,540 --> 00:06:17,570 Gigabit zero is enabled which using static access administrative mode and is operating as a static access 87 00:06:17,570 --> 00:06:18,110 port. 88 00:06:18,320 --> 00:06:25,700 It's in VLAN two at the moment, so all PC to be able to ping PC for let's do the ping again. 89 00:06:25,910 --> 00:06:27,440 Ping fails from. 90 00:06:28,420 --> 00:06:30,130 Four out of four, two out of two. 91 00:06:30,550 --> 00:06:33,190 And it also fails in the reverse direction. 92 00:06:33,400 --> 00:06:36,400 These two are not able to ping each other. 93 00:06:36,730 --> 00:06:41,920 Let's disable this port and force the traffic to go through the hub and then do a Wireshark capture 94 00:06:41,920 --> 00:06:43,120 to see what's going on.