1 00:00:09,000 --> 00:00:15,660 This is one of multiple videos discussing Layer 3 switching. In a previous video I showed you how to 2 00:00:15,660 --> 00:00:19,950 configure a switch with layer 3 functionality. 3 00:00:20,160 --> 00:00:28,910 So I showed you how to enable IP routing on a switch to allow that switch to route between one VLAN and 4 00:00:28,980 --> 00:00:30,330 and another. 5 00:00:30,330 --> 00:00:38,200 We also configured two routers to act as PCs and we were able to ping from one router to another. 6 00:00:38,250 --> 00:00:46,740 What I'll do now is extend the topology by bringing in some docker PCs. 7 00:00:46,820 --> 00:00:54,150 These are essentially lightweight PCs that allow us to boot up Linux very quickly. 8 00:00:54,170 --> 00:00:56,200 So what I'll do on the first PC 9 00:00:59,030 --> 00:01:02,420 is configure it in a fourth VLAN. 10 00:01:05,720 --> 00:01:17,380 So I'll give it an IP address of 10 141 and a default gateway of 10 14 254. I'll also set the 11 00:01:17,380 --> 00:01:32,090 DNS server to 10 14 254 and click save. I'll connect the PC to gigabit 02 on the switch 12 00:01:32,130 --> 00:01:35,940 So these two ports are in VLAN 2 and 3 13 00:01:36,060 --> 00:01:45,450 and what we'll do now is configure the port in VLAN 4. I'll start up the docker PC and open up a 14 00:01:45,450 --> 00:01:46,590 a console to it. 15 00:01:47,590 --> 00:01:54,090 So here's the console IF CONFIG shows us the IP address of the PC 16 00:01:54,190 --> 00:01:58,960 one of the advantages of Docker is that it boots up extremely quickly. 17 00:01:58,960 --> 00:02:01,700 So it was almost an instant boot. 18 00:02:01,720 --> 00:02:06,910 Now the PC can ping the switch because we need to configure the switch. 19 00:02:06,990 --> 00:02:11,360 So at the moment pings are failing. 20 00:02:11,510 --> 00:02:16,080 So I'll go onto the switch and have a look at the interfaces configured, 21 00:02:16,100 --> 00:02:18,890 so show IP interface brief. 22 00:02:19,340 --> 00:02:27,860 Notice we don't have a layer 3 interface in VLAN 4. We need to configure this IP address on the 23 00:02:27,860 --> 00:02:32,210 switch to allow that PC to ping out to VLAN 4. 24 00:02:32,600 --> 00:02:40,940 We also need to configure VLAN 4 and put this interface into VLAN 4. So CONFT VLAN 4 25 00:02:41,630 --> 00:02:51,080 show VLAN brief, we've now created a VLAN 4 and it's been added to the VLAN database. 26 00:02:51,080 --> 00:02:57,530 That however does not create the SVI or virtual switched interface. 27 00:02:57,530 --> 00:03:04,920 We need to type interface VLAN 4 to create the SVI and configure the IP address on the switch. 28 00:03:07,970 --> 00:03:12,890 So show IP interface brief 29 00:03:12,920 --> 00:03:18,780 the SVI is created. IP address is assigned but the interface is down. 30 00:03:19,370 --> 00:03:28,660 So we need to no shut it, show IP interface brief again allows us to see the interface but it's currently 31 00:03:28,660 --> 00:03:40,810 down because no interfaces have been allocated to that VLAN. So we need to put this interface into 32 00:03:42,070 --> 00:03:48,800 VLAN 4, so switchboard access VLAN 4. 33 00:03:48,810 --> 00:03:55,500 Now when we use the command show IP interface brief we should see that this interface comes up that 34 00:03:55,500 --> 00:04:03,600 may not happen immediately but after a while, we should see that that interface comes up assuming that 35 00:04:04,960 --> 00:04:14,710 gigabit 02 is in the right VLAN which it is and assuming that that interface is up pup which 36 00:04:14,710 --> 00:04:21,360 it is. Noticed now VLAN 4 is up. So back on the PC 37 00:04:22,750 --> 00:04:33,540 previously the PC couldn't ping its default gateway but now it can and hopefully it will be able to ping router 38 00:04:33,560 --> 00:04:35,870 2, which it can 39 00:04:36,360 --> 00:04:40,040 and we can prove that by looking at router 2. 40 00:04:40,170 --> 00:04:52,020 I'm currently running a debug to show debug on router 2 shows that IP ICMP debugging is enabled. So 41 00:04:52,020 --> 00:05:01,350 we should be able to ping router 2 and see the debugs which we do. 42 00:05:01,930 --> 00:05:09,600 We should also be able to ping router 1 which we can once again this PC has an IP address of 10 1 43 00:05:09,610 --> 00:05:14,150 41 on the router acting as PC 2. 44 00:05:14,160 --> 00:05:18,050 We should be able to ping that PC which we can. 45 00:05:18,230 --> 00:05:28,480 So we've now enabled three VLANs on this layer 3 switch I'll configure a fourth interface and 46 00:05:28,480 --> 00:05:38,840 connecte it to the second docker PC I'll change the IP address of that PC 47 00:05:42,220 --> 00:05:55,620 to 10.1.5.1 default gateways 10 15 254 and I'll set the DNS server to 10.1.5.254 48 00:05:57,160 --> 00:06:04,430 clicks save, startup the PC open up a console to it, PCs booted. 49 00:06:04,430 --> 00:06:17,940 So IF CONFIG IP address is 10 151 PC will not be able to paying the first PC on the left until we've 50 00:06:17,940 --> 00:06:27,620 configured the switch. So I'll configure the switch while leaving that ping going in the background. 51 00:06:28,040 --> 00:06:36,600 So first thing we need to do is configure a VLAN. So CONF T VLAN 5 in this case. 52 00:06:36,600 --> 00:06:46,430 So show VLAN brief VLAN 5 is created PC can still not ping the other PC yet. 53 00:06:47,810 --> 00:06:55,650 Because we have to put the interface into the right VLAN gigabit 54 00:06:55,720 --> 00:07:08,000 03 is currently in VLAN 1. So interface gigabit 03 switch port access VLAN 5 show interface 55 00:07:08,000 --> 00:07:15,060 gigabit interface 03 switch port. The port is now in VLAN 5 56 00:07:15,470 --> 00:07:22,940 but the PC can still not ping PC1 because we have to create a switched virtual interface. 57 00:07:22,940 --> 00:07:27,890 We have a switched virtual interface for VLAN 4 but not for VLAN 5. 58 00:07:27,890 --> 00:07:36,980 So interface VLAN 5, IP address 10 15 254 I'll no shut it. 59 00:07:39,190 --> 00:07:48,430 Interface VLAN 5 has come up show spanning tree ports are forwarding and pings are starting 60 00:07:48,430 --> 00:07:49,630 to succeed. 61 00:07:50,190 --> 00:07:56,460 So PC 2 can ping PC 1. 62 00:07:56,690 --> 00:08:07,180 So I've now got four interfaces on this layer 3 switch configured for inter VLAN routing. I've configured 63 00:08:07,190 --> 00:08:11,660 the VLANs and configured inter VLAN routing on the switch. 64 00:08:11,660 --> 00:08:14,440 In other words it's acting as a layer 3 switch. 65 00:08:14,990 --> 00:08:17,480 That's because IP routing is enabled. 66 00:08:17,510 --> 00:08:23,460 If I disable IP routing on the switch the pings will fail. 67 00:08:23,780 --> 00:08:30,950 Notice the sequence numbers at 49 and I stop there to find enable IP routing. 68 00:08:30,980 --> 00:08:33,990 Notice the pings start succeeding once again. 69 00:08:35,530 --> 00:08:41,890 You need to have IP routing enabled on a switch to allow it to do inter VLAN routing as well as to 70 00:08:41,890 --> 00:08:44,750 allow it to support routing protocols. 71 00:08:45,280 --> 00:08:50,320 So that was an example of how to configure a layer 3 switch into VLAN routing. 72 00:08:50,320 --> 00:08:54,600 I hope you found the video useful if it's been of benefit to you. 73 00:08:54,640 --> 00:08:57,410 Please subscribe to my YouTube channel. 74 00:08:57,560 --> 00:08:59,350 I wish you all the very best.