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 sign up via the link in the description to get all of the lab files for this course, so you can 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, and it includes all of these guided labs to not only help you get hands-on practice configuring and troubleshooting, but also deepen your understanding of the exam topics. I used it myself when studying for my certifications, so I feel confident about recommending it to all of you. If you want to get your own copy of NetSim, please follow the link in the video description. In this lab we will configure NTP in this network. R1 will synchronize to SRV1 over the Internet, and then R2 and R3 will synchronize to R1. Unfortunately some of the commands I showed you in the lecture aren’t available in Packet Tracer, such as the CLOCK SUMMER-TIME command, the NTP SOURCE command, and some others. But there are still many NTP configurations we can practice, so let’s get started. In step 1 we will configure the time on R1, R2, and R3 to 12PM on December 30th 2020. Note that we haven’t configured the time zone yet, so this will be in UTC. I’ll go on R1 first. ENABLE. CLOCK SET 12:00:00, that’s hours, minutes, and seconds, Dec 30 2020. Let’s check the clock. SHOW CLOCK DETAIL. Okay, the time is correct and the source is user configuration. Later we’ll configure NTP, however something I didn’t mention is that NTP can take quite a long time to synchronize. But if you manually configure the time on the device close to the time of the NTP server, the synchronization process will be a little quicker. I configured the NTP server, SRV1, for the same time so this should make it quicker. Actually, while we’re here I’ll do step 2 on R1 and configure the time zone. CONF T. CLOCK TIMEZONE JST 9. If you’re not sure how many hours your time zone is offset from UTC, do a Google search to find out. Let’s check once more. DO SHOW CLOCK DETAIL. Okay, so the clock is now 9 hours ahead of the UTC time I configured. Next I’ll do R2. ENABLE. CLOCK SET 12:00:00 Dec 30 2020. And I’ll configure the time zone. CONF T. CLOCK TIMEZONE JST 9. And then check. DO SHOW CLOCK DETAIL. Okay, looks good. And finally I’ll do the same on R3. ENABLE. CLOCK SET 12:00:00 Dec 30 2020. And the time zone. CONF T. CLOCK TIMEZONE JST 9. And I’ll check. DO SHOW CLOCK DETAIL. Okay, no problem. The clocks on R1, R2, and R3 don’t match at the moment, but that’s fine. That will be fixed when we enable NTP later. Step 3 is to configure R1 to synchronize to NTP server 1.1.1.1, that’s SRV1 here. So I’ll return to R1 and do that. NTP SERVER 1.1.1.1. That’s it. Let’s check. DO SHOW NTP ASSOCIATIONS. Okay, 1.1.1.1 was configured but as you can see the ‘sys.peer’ asterisk isn’t showing yet. This can take quite a while, especially in Packet Tracer, so I’ll click these arrows here a bunch of times to fast-forward the simulation. Okay, hopefully that’s enough, I’ll go back to R1. But the console has timed out because of inactivity, so I’ll use ENABLE again and let’s check. SHOW NTP ASSOCIATIONS. Okay, the asterisk is there now. So, what stratum is 1.1.1.1? It’s stratum 1, as you can see here. So, now that R1 is an NTP client it is an NTP server also, what is its stratum? It should be 2, because it is syncing to a stratum 1 server. Let’s check. SHOW NTP STATUS. Okay, that is correct, stratum 2. And let’s check R1’s clock. SHOW CLOCK DETAIL. Okay the time source has changed to NTP. So, that’s all for step 3. In step 4 we must configure R1 as a stratum 8 NTP master. Why would we do this? R1 is already acting as an NTP server because it is syncing to SRV1, so R2 and R3 should be able to use R1 as an NTP server. However, what if R1 stops being able to sync to 1.1.1.1? If we configure R1 as an NTP master, that can serve as a backup clock for R2 and R3 to sync to. So let’s do that here on R1. CONF T. NTP MASTER. It says to configure R1 as a stratum 8 master, and that is the default so we don’t need to specify the stratum. Next we must configure R2 and R3 to synchronize to R1 with authentication. Okay, since I’m on R1 already I’ll configure the authentication here first. First, enable NTP authentication. NTP AUTHENTICATE. Then, create the key. NTP AUTHENTICATION-KEY 1, you can use whatever number you want, MD5, then the key itself. No password is specified in the instructions, so use whatever you’d like. I’ll use ‘jeremysitlab’. Finally I’ll configure key 1 as a trusted key. NTP TRUSTED-KEY 1. Okay that’s all for R1. Next I’ll configure R2. ENABLE. CONF T. First I’ll enable NTP authentication. NTP AUTHENTICATE. Then create the key. NTP AUTHENTICATION-KEY 1 MD5 jeremysitlab. Then configure key 1 as trusted. NTP TRUSTED-KEY 1. Finally I’ll configure R1 as R2’s NTP server. NTP SERVER 192.168.12.1 KEY 1. That configures R1 as R2’s NTP server, and specifies that R2 should use key 1 to authenticate R1. As the note says in step 4, the NTP source command isn’t available in Packet Tracer, so instead of using a loopback interface I just configured R1’s G0/1 interface as the NTP server. The reason you need the NTP SOURCE command is that, if you configure R1’s loopback interface as R2’s NTP server, but the replies from R1 come from the IP address on the physical interface, R2 won’t sync to R1. Now I’ll fast forward the simulation again, and now hopefully R2 has synced to R1. Let’s check. END. SHOW NTP ASSOCATIONS. Yep, it has synced to R1. And let’s check R2’s clock. SHOW CLOCK DETAIL. Okay, the time source is NTP. Since I’m on R2 I’ll do step 5 also, which is to configure NTP to update the hardware calendar. CONF T. NTP UPDATE-CALENDAR. Okay now let me show you something strange about packet tracer. I just configured NTP UPDATE-CALENDAR, so let’s check the calendar. EXIT. SHOW CALENDAR. But it doesn’t work. SHOW, and I’ll use the question mark. As you can see, there is no SHOW CALENDAR command in Packet Tracer. So, there is the NTP UPDATE-CALENDAR command, but for some reason you can’t even view the calendar. Okay, I’ll do the same configurations on R3. ENABLE. CONF T. NTP AUTHENTICATE. NTP AUTHENTICATION-KEY 1 MD5 jeremysitlab. NTP TRUSTED-KEY 1. And then I’ll specify R1. NTP SERVER 192.168.13.1 KEY 1. It’s pointless in Packet Tracer, but I’ll update the calendar. NTP UPDATE-CALENDAR. That’s it, now I’ll fast forward the simulation. And let’s see if R3 synced to R1. ENABLE. SHOW NTP ASSOCIATIONS. Okay, looks good. And how about the clock? SHOW CLOCK DETAIL. Okay, the time source is NTP, looks good. Once again, this is pointless in Packet Tracer but I’ll configure R1 to use NTP to update its calendar. ENABLE. CONF T. NTP UPDATE-CALENDAR. Okay, we have completed all of the steps. Originally I had another step to configure a symmetric active peering between R2 and R3, but that command is also unavailable in Packet Tracer. But in this video we practiced many of the NTP commands we looked at in the lecture video. That’s all for this lab. Next let’s take a look at a bonus lab in Boson Software’s NetSim for CCNA. Okay here's today's Boson NetSim lab preview. The lab I have selected it 'configuring NTP 1'. So, NetSim for the CCNA actually has 5 labs for NTP, as you can see here. So I picked the first one. It seems to be a pretty simple lab about NTP. Here is the topology, three routers. And these are the commands you need to know. And these are all commands you already know. CLOCK SET, to set the time. NTP MASTER. NTP SERVER. And some SHOW NTP commands. Okay here are the tasks. Task 1 says 'perform initial configurations.' So in this task you just configure the IP addresses on the interfaces and enable them. So I actually completed this task, here you can see the CLI of Router1. So I finished this task and we can go straight to task 2, 'configure NTP'. So let's do that. Step 1 says 'Is Router1, Router2, or Router3 currently running NTP?' Let me check with SHOW NTP STATUS. No, NTP is not enabled on Router1. Or Router2. Or Router3. Okay, configure the date and time on Router1 to be July 25th 2013, that's my birthday, July 25th, 9AM. Alternatively you may use your local date and time. Okay so I'll do that on Router1. CLOCK SET 9:00:00 25 JUL 2013. Okay, let me see. SHOW CLOCK. Alright, looks good. Configure Router1 to be an NTP master using a stratum of 3. Okay, CONF T. NTP MASTER, and here we specify the stratum number. Once again, the default if you enter the command as is, the default is 8. So we want to set it to 3, so NTP MASTER 3. Configure Router2 to be an NTP client. Okay so, we'll use the IP address of Router1's Serial0/0/0 interface which is here, alright. CONF T. NTP SERVER 10.0.12.1. Okay, and I'll leave it like that. I think in task 3 we'll actually verify that this is working. So I'll go straight to step 5. Configure Router3 to be an NTP client. You should use the address of Router2's Serial0/0/1 interface, okay. So that is this one here. CONF T. NTP SERVER 10.0.23.2. Okay, and that's it for task 2. Okay finally task 3, verify NTP. On Router1, observe the status of NTP. What are the stratum and reference peer address? Okay, SHOW NTP STATUS. Stratum is 3, because we configured NTP MASTER 3. And the reference clock is a loopback address on Router1. Okay, let's check on Router2. SHOW NTP STATUS. Okay the clock is synchronized, so that means it has synchronized to Router1 and the stratum is 4 as expected, 1 higher than Router1. And also we can see the reference is Router1's address. Okay step 3, verify that Router1 is the NTP master. Okay well I can see that here, because that's Router1's address. But I'll also check the associations table. Okay, so there it is. The address of Router1. It is the master here. Notice that the output is a little different than in Packet Tracer or in the lecture video. This must be a different version of Cisco IOS. Okay so that was step 3. Step 4, on Router2, observe all NTP associations. Okay well I just did that. Or maybe step 3 was supposed to be on Router1, whatever. I'll go on to step 5 and we'll check out Router3. Okay, looks like it has synced to Router2 here. What are the reference peer address and stratum? The stratum of its peer is 4, so Router3 must be stratum 5 now. Yes it is, stratum 5. Okay in steps 3, 4, and 5 in this task you observed each router's NTP associations. Why were the reference peer addresses different on each router? Oh that is because they are syncing to different clocks. So, Router1 is syncing to its internal clock. So the reference clock is a loopback address. Router2 is syncing to Router1, so the address is Router1's address. And Router3 is syncing to Router2 so the address is Router2's address. On Router2 and Router3 display the clock and verify that the source of the time is NTP. Okay, SHOW CLOCK DETAIL. Looks good. Source is NTP. And how about on Router3? Okay, time source is NTP. So that's all for this lab. Now I will use the 'grade lab' function by clicking this icon here and let's see if I did everything correctly. Okay looks good. You completed the lab successfully. Notice that nothing is highlighted in the configurations of each device. If there are any missing commands or extra commands they will be highlighted in red or blue. Okay so that's a quick look at Boson NetSim for the CCNA. As I've said before, there are over 100 detailed, guided labs like this. Some of them are simple, some are very complex, but they're all very useful to study for the CCNA. So if you want to get Boson NetSim, please follow the link in the video description. Before finishing today’s video I want to thank my JCNP-level channel members. To join, please click the ‘Join’ button under the video. Thank you to Biraj, Magrathea, Samil, Junhong, Njabulo, Benjamin, Tshepiso, Justin, Prakaash, Nasir, Erlison, Apogee, Marko, Daming, Jhilmar, Ed, Value, John, Funnydart, Velvijaykum, Mark, Yousif, Boson Software, Devin, Lito, Yonatan, and Vance. Sorry if I pronounced your name incorrectly, but thank you so much for your support. This is the list of JCNP-level members at the time of recording by the way, December 31st 2020. If you signed up recently and your name isn’t on here don’t worry, you’ll be in future videos. Thank you for watching. 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