Welcome to Jeremy’s IT Lab. This is a free, complete course for the CCNA. If you like these videos, please subscribe to follow along with the series. Also, please like and leave a comment, and share the video to help spread this free series of videos. Thanks for your help. Also, remember to download this practice lab from the link in the description and try it out yourself in packet tracer. If you want more labs like these, I highly recommend picking up Boson’s NetSim for the CCNA, click the link in the video description to check it out. It’s a network simulator like packet tracer, but it’s even better, you can use it up to CCNP level even, whereas Packet Tracer is too limited to do much beyond CCNA-level. Here, you can see all of the labs available NetSim for CCNA. These are all detailed, guided labs that not only help you practice what you’ve learned, but really test your understanding, so I think NetSim is a fantastic study tool for the CCNA. If you want more practice relevant to what we’re covering now at this point in the course, look here in the ‘network access’ section. VLANs, Trunking, this is all stuff you’ve been studying over the past few videos. Make sure to stick around to the end of this video for a preview of one of these labs. If you want to grab a copy of NetSim for CCNA, follow the link in the video description, I highly recommend it. Okay, let’s get started with today’s lab. First off, all of these devices are preconfigured so they are like they were at the end of Day 17’s lab, except SW2 has been replaced with a Layer 3 switch, aka multilayer switch. So, all of the hosts are already in the correct VLANs, SW1 and SW2 are connected with a trunk, and R1 and SW2 are connected using router on a stick. So what we’ll be doing is changing this router on a stick configuration, to do inter-VLAN routing via SVIs on SW2, just like in the lecture video. Step 1 is to replace the router on a stick configuration with a point-to-point Layer 3 connection. I’ll start on R1 first. Enter privileged exec mode with ENABLE, and then let’s do a few show commands. First, let’s check the running config of G0/0 and it’s interfaces. SHOW RUN. By the way, you can press enter to scroll through the running-config one line at a time, or the spacebar to scroll one screen at a time. So, the physical interface itself has only the default configurations, all I’ve done is enable it with NO SHUTDOWN. Under it you can see the three subinterfaces. Let’s check the status of the interfaces. SHOW IP INTERFACE BRIEF. G0/0 and its subinterfaces are all UP/UP. Now, let’s remove the subinterfaces. Enter global config mode with CONF T. Then delete the subinterfaces with this command: NO INTERFACE G0/0.10. Then, hit the up arrow, and let’s change this to .20. And one more time, for .30. Let’s check the config again. DO SHOW RUN. So, the subinterfaces have disappeared. And let’s check their status. DO SHOW IP INTERFACE BRIEF. Now, this is a difference between packet tracer, and what I showed in the lecture video. When I do the lecture videos, I used GNS3, which runs actual Cisco IOS software, unlike packet tracer, which is just a simulator. On GNS3, the subinterfaces still appear with a status of ‘DELETED’ until you restart the device, but as you can see here they are immediately removed in packet tracer. Now, let’s configure G0/0 with an IP address. INTERFACE G0/0. IP ADDRESS 10.0.0.194 255.255.255.252. Okay, that’s all we need to do on R1. In the lecture video I did DEFAULT INTERFACE G0/0 before configuring the IP address, but that’s not actually necessary, since it already has the default settings. Okay, next let’s configure SW2’s G1/0/2 interface. Enter privileged exec mode with ENABLE. And let’s check the config of G1/0/2. SHOW RUN. There it is. Notice this layer 3 switch requires the SWITCHPORT TRUNK ENCAPSULATION DOT1Q command. The model of switch used in the previous lab didn’t require this. Okay, let’s return the interface to the default configuration. Enter global config mode, CONF T. Then, DEFAULT INTERFACE G1/0/2. When testing this lab out before I had to do the command twice for it to work, that might be a packet tracer issue, but I’ll issue the command once more by using the up arrow. And next let’s check. DO SHOW RUN. Okay, so G1/0/2’s configurations have been removed. Let’s configure it. INTERFACE G1/0/2. Let’s try to add an IP address. IP, then I'll use the question mark. Notice there is no option for ADDRESS, why is that? It’s because this interface is still in layer 2 mode. Let’s put it into Layer 3 mode. NO SWITCHPORT. Okay, let’s try again. IP, then question mark. Now we have lots of options here, including address, so let’s set the address. ADDRESS 10.0.0.193 255.255.255.252. Finally, let’s configure the default route here on SW2. EXIT. And let’s check the current routing table. DO SHOW IP ROUTE. No routes appear, even though we should have connected and local routes for the interface we configured, why is that? It’s because we haven’t enabled IP ROUTING on the switch yet, so let’s do that. IP ROUTING. And let’s view the routing table once again. DO SHOW IP ROUTE. Notice that only a connected route appears, no local route. When I showed you the command in the lecture video, both routes appeared properly, connected and local. So I think this might be an issue with packet tracer, a local router should appear here too. Anyway, let’s configure that default route. IP ROUTE 0.0.0.0 0.0.0.0, and the next hop is 10.0.0.194, R1’s address. DO SHOW IP ROUTE. Okay, the default route has been added. That’s all for step 1. Step 2 is to configure the SVIs on SW2. First off, let’s check if the necessary VLANs exist. Remember, an SVI won’t have a status of UP/UP if its VLAN doesn’t exist. DO SHOW VLAN BRIEF. Okay, VLANs 10, 20, and 30 exist. Let’s configure those SVIs, it’s fairly simple. INTERFACE VLAN 10. Okay, the SVI has been created, now all we have to do is assign the IP address, the last usable address of the subnet in this case. IP ADDRESS 10.0.0.62 255.255.255.192. That’s it. Let’s do VLAN 20. INTERFACE VLAN 20. IP ADDRESS 10.0.0.126 255.255.255.192. Finally, VLAN 30. INTERFACE VLAN 30. IP ADDRESS 10.0.0.190 255.255.255.192. EXIT. Now let’s check if the interfaces are UP/UP. DO SHOW IP INTERFACE BRIEF. Okay, looks good, the VLAN10, 20, and 30 SVIs are all UP/UP. So, our inter-VLAN routing should be functioning now. Let’s test by pinging between VLANs. I’ll do a ping from PC7 in VLAN10 to PC3 in VLAN30. First, in real time mode I’ll test the ping. PING 10.0.0.129. Okay, so the ping gets through. I still get questions sometimes about why the first one or two pings fail, that’s because PC7 needs to ARP for the MAC address of its default gateway, I’ve explained ARP in a previous video. Now let’s go into simulation mode to make sure the traffic is NOT routed by R1, but instead by SW2. And let’s try that ping again. PING 10.0.0.129. Okay, notice that the ping goes to SW2, and SW2 sends it directly to SW1, without having to send it to R1. That’s because SW2 routed it from the VLAN10 SVI to the VLAN30 SVI within its own software. Okay, let’s return to realtime mode. Finally, just to test if our default route to R1 works, let’s try a ping to an address in the Internet, 1.1.1.1. Note that I already configured static routes on R1 and the Internet router, so you don’t have to configure anything else. Let’s try that ping. PING 1.1.1.1. Okay, so the ping to the Internet works as well. That’s all for this lab. Okay let's move on to today's NetSim lab preview. The lab I've chosen for today is InterVLAN Routing 2, and I've already loaded it up so let's get started. The network topology is the same as last time. One router, two switches, four PCs, but instead of setting up the network we will troubleshoot some problems on the network. So, there are three lab tasks today. Task 1, verify and correct workstation configurations. These are the PCs. Task 2, verify and correct switch configurations. And task 3 is router configurations. So, I think for today's preview we'll do task 1 and task 2. So, task 1. A user has reported that PC3 is unable to ping any other device on the network, including devices that reside on the same VLAN as PC3, which is VLAN10. Okay, so it looks like the devices in VLAN10 are PC1 and PC3. And VLAN12, PC2 and PC4. Okay, 1 and 3, VLAN10. 2 and 4, VLAN12, okay. Here we are, okay. And then there's some more explanation. All steps in this task should be performed on PC3. Okay, let's go to step 1. Verify the problem by attempting to ping every other IP address on the network. All pings should fail. Okay, I won't ping every address but let's go on PC3. Still Router1, sorry. PC3, console. There we go. And let's ping the default gateway, which is 192.168.100.1, this subinterface on Router1. And the ping should fail. Yep, looks like it's failing. Okay, I'll stop that. How about PC1 in the same VLAN? 100.2. Yep, that's failing as well. And let's do one in VLAN12. How about .130, which is PC2? Okay. So, all the pings are failing as expected. Step 2, according to the network documentation PC3 should operate in VLAN10. Verify the IP address configuration. Okay, so here is the correct configuration for PC3. Let's see what the actual current configuration is. IPCONFIG /ALL. IP address is correct. Subnet mask should be /25, ending in .128, but this is /24, ending in .0. So that is incorrect. The default gateway is correct, however. Okay, so the IP configuration is not correct. Correct any IP address configuration problems you find. So, the way to set the IP address for a PC in NetSim is this command here. Note that this is just for PCs in NetSim. IPCONFIG /IP (ip-address) (subnet-mask). Okay, 192.168.100.3, and then the /25 prefix length. And let's confirm our configuration. Okay, looks good. Attempt to ping every other IP address on the network. Do all the pings succeed now? Okay, let's do some more pings. How about the default gateway? 100.1. Okay, still fails. How about PC1? Okay, that still fails. And we'll do one in VLAN12, PC2. Okay, that still fails. I'm using Ctrl-C to stop these pings, by the way. Okay, so we corrected IP address configuration, but that didn't solve the problem. Okay, task 2. After verifying PC3's configuration in the previous task, you should begin examining other devices on the network to determine whether other problems exist. Okay, so step 1. List two or more causes of inter-VLAN routing problems on Layer 2 switches. Okay, so this is something I really like about NetSim. It really tests your understanding by asking good questions like this. So, what are two possible problems? Okay, one could be..perhaps the PC is in the correct, sorry the incorrect VLAN. It's supposed to be in VLAN10. Maybe it's in VLAN12 or a totally different VLAN. So, that's one possible cause. Let's do one more. How about...this is probably a trunk connection between the two switches, or it should be. You might have forgotten the SWITCHPORT MODE TRUNK command. Or perhaps the correct VLANs are not allowed. So maybe VLAN10 is not allowed on this trunk, therefore PC3's traffic cannot pass between the two switches. Okay, so those are two possible causes. According to the network documentation, PC1 resides on the same VLAN as PC3. From PC1 and PC3, attempt to ping each subinterface on Router1. What can you surmise from the results of these pings? Okay, so first from PC3. Well, we already tried the ping but I'll just do it one more time. 100.1. This subinterface cannot be pinged from PC3. Did it say both subinterfaces? Yes, each subinterface on Router1, okay. So the subinterface for VLAN12 should not work also. .129. Okay, yes, the ping fails. Now let's try from PC1, also in VLAN10. 192.168.100.1. Okay, the ping works. How about the other subinterface? It works as well. Okay, so PC3 cannot ping either subinterface. PC1 can ping both. So what can you surmise from that? Well, I'd say the problem is either on Switch2 or in the connection between Switch1 and Switch2, because Switch1 seems to be able to route between the VLANs no problem. Or, Switch1 doesn't do the routing, but Router 1 does the routing here. But PC1 can ping through Switch1 to Router1. PC3 cannot though, so there's either a problem on Switch2 or on either Switch1 or Switch2 on this trunk connection here. Okay next one, on Switch1, display VLAN information. What ports are operating in the same VLAN as PC1 and PC3? Okay, Switch1, console. ENABLE. SHOW VLAN BRIEF is the command we want. So, VLAN10 is the VLAN. Only FastEthernet0/3, which I believe was PC1's VLAN, yes. So this configuration seems fine. Yeah, so the answer is FastEthernet0/3. On Switch1, display interface trunk information. Which VLAN is the native VLAN and which ports are trunk ports? SHOW INTERFACES TRUNK. Okay, so as expected FastEthernet0/1 and 0/2 are trunk ports and the native VLAN is 1 on both, the default native VLAN. Okay, and then go to Switch2, okay. Switch2, ENABLE. SHOW VLAN BRIEF. Okay, so no ports are in VLAN10. FastEthernet0/3 and 0/4 are both in VLAN12. Okay, so let's go to number 6. Based on the topology and IP address configurations, which ports on Switch2 should be operating in VLAN10? That is probably FastEthernet0/3. Yes, it is, so here is an issue. PC3 in VLAN10, or should be in VLAN10. But it is currently configured in VLAN12, and its subnet is also the VLAN10 subnet. So I think we're gonna have to change that. There we go, step 8. Or sorry, step 7. What mode is Switch2's FastEthernet0/3 port in? Okay, so this is a command that I haven't showed you yet. SHOW INTERFACES F0/3 SWITCHPORT. I don't think I've showed you it yet. Administrative and operational mode are both static access, so this is an access port. It's been configured with the command 'SWITCHPORT MODE ACCESS'. So, that's the answer to number 7, access mode. Number 8, correct the VLAN configuration. Okay, so that is easy. CONF T. INTERFACE F0/3. It should be in VLAN10, so SWITCHPORT ACCESS VLAN 10. And then number 9 is verify the new VLAN configuration. DO SHOW VLAN BRIEF. Okay, that's better. FastEthernet0/3 is in VLAN10. Next, number 10, on Switch2 display interface trunk information. Okay, DO SHOW INTERFACES TRUNK. So, FastEthernet0/1 is a trunk. That's correct. Native VLAN is 1, same as Switch1. And I didn't point this out on Switch1, but all VLANs are allowed. The allowed and active VLANs are 1, 10, and 12. So same as Switch1. So the trunk configuration here actually looks fine, between the two switches. Okay next, from PC3 do some more pings again. Do all the pings succeed now? Let's see. So first the default gateway. Okay, the ping works. So looks like that VLAN issue was the main problem. How about PC1, in the same VLAN? Yep, looks good. How about PC2, in VLAN12? Okay, it does not work. How about PC4? Okay, PC4 doesn't work either. Okay, so there is definitely an issue there. From PC2, attempt to ping every other device in the topology. Okay, PC2 is in VLAN12, connected to Switch1. So let's open the CLI here. First, ping its default gateway. 100.129. Okay, PC2 cannot even reach its default gateway. How about PC4 in the same VLAN? Okay, this works. So it can ping the other PC in the same VLAN, but it cant ping its default gateway. How about PCs in other VLANs? It shouldn't be able to reach them because it can't reach the default gateway. Yep, as expected it doesn't work. Okay, so clearly we still have an issue here. So PC3 seems to be operating fine. But PC2 can ping PC4 in the same VLAN, but it can't ping its default gateway, which is the subinterface here on Router1. So clearly an issue still remains in the network. So, I think we will solve those issues here in task 3. But I'll leave it here for today. If you want to pick up a copy of NetSim for yourself, please follow the link in the description. I highly recommend it, it's great additional practice for your CCNA and as you can see there are plenty of labs from network fundamentals, network access, IP connectivity, IP services, security fundamentals. This'll give you all the practice you need to get ready for the exam. So again, please follow the link in the description and get a copy. Thank you for watching. Please subscribe to the channel, like the video, leave a comment, and share the video with anyone else studying for the CCNA. If you want to leave a tip, check the links in the description. 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