ERRATA: Typo at 16:00: “BackboneFast allows SW3 to expire the *made* age timers...” should be ”expire the *max* age timers...” At 37:15, SW1's port connected to the PC should be G0/3, not G0/0.
Don't you think, that SW3's G0/1 should be the root port and not G0/2? They have same root cost, same neighbour BPDU, but G0/1 has lower port ID giving it advantage to become root over G0/2
There is on one side courses/books that briefly tell you about some concepts, tell you what to remember and give definitions to learn by heart, making it really boring, and on the other side Jeremy's lessons that make you really understand all these concepts in detail and making it interesting at the same time! Can you believe that the Official Cert Guide Library from Cisco Press is not even mentioning non-designated ports, not talking about which port roles send/receive BPDUs, and, what I consider the worst: giving extremely poor explanations about path costs, alternate ports, and backup ports (they are just mentioned)? Thank you, for real, for all this time you invested in us, making it so interesting!
I've noticed Jeremy likes to explain things in more detail than is necessary for the CCNA. This is actually a good thing in my opinion because the extra detail helps me remember concepts better than someone saying "this is the way it is just because it is". With that in mind, if you retain everything from the official cert guide, its plenty to get an excellent score on the exam, it's just not necessarily easy to do that when the content is so dry and poorly explained.
Jeremy, i have taken 3 times CCNA courses since version 4.0. but you are by far the best teacher. Really clear concepts and great methodology and examples. Really, thank you for sharing your knowledge and effort on this course.I hope you can finish all the topics!
Hi Jeremy. I started to read the official documentation for CCNA, before knowing about this course, but I didn't understand 100% the STP. I was a bit frustrated, but then I discovered your course. I am really happy, you are a great teacher and explain the topics in a simple way that it's easy to understand. Now, I first watch your video and practice with labs and then I read the official documentation. It changed my world. Thanks so much for this course !!!
I had already done the CBT Nuggets videos and read Todd Lammle books which are all great, but left me a little iffy on some concepts, after watching your videos I am finally understanding everything that I missed or was unsure about! Thank you so much, I was about to give up after not understanding it well from those other two sources.
Although you said that you don't have to much time for the videos, keep it going to make the rest of the videos early, you are such a good teacher. I'm studying CCNA from your videos.
I gotta say, you def. made this easier by teaching us the parts of STP that may not be on the exam, too. I found myself struggling to grasp Classic STP for a few days. But after some studying + the flashcards and lab, I mostly got it down. Now, learning RSTP feels like a breeze. That's "wax on, wax off" type stuff. Markings of a GREAT teacher. 😄
Thank you so much for this...i love the labs and I know the more I do them, the better off I'll be...I'm learning a lot with the labs and that's something that distinguishes between this channel and others. Keep up the great work!!!!
I was having some confusion with the RSTP and after having watched your video, everything became crystal clear.. great video and very well implemented with examples at the right time plus the Boson exam sim is a great bonus.. Can't thank you enough.. looking forward to your next CCNA videos.. cheers!
Dear Jeremy, Please forgive me for not watching your videos for a while now. I've been using the Boson Simlab for practice and have not be in on RUclips. You're still awesome. Your friend you've never met, Timmy Tim McTimson
I must be Rapid SPT myself, because I'm basically in a "Blocking, Listening and Disabled states are combined, and the Listening state is not used" state every day at work. More motivation for me to study and pass CCNA in hopes of landing a better job. If not for Jeremy I'd probably have given up already.
After I had watched your STP 1, 2 and this one, I really felt regret for missing your channel to watch and learn from you. Thanks a lot for your kind contribution. with Best Regards,
Another excellent video. Thank you. I especially benefited from quiz question 4 and your subsequent detailed explanation. I appreciate the work you put into these questions.
Wow, me getting the RSTP Quiz 4 question right was satisfying. Adding hubs into the mix really trips me up, but I am proud I got it right :) And it's all thanks to you, Jeremy. Thank you so much.
I got Quiz 4 wrong the first time then watched the entire video again with playback speed 1.5x and then finally understood how to assign the port roles properly, thank you!
So my network diagram I made was ALMOST exactly as shown at 38:45 with one exception: the G0/1 link on SW1 connecting to G0/2 on SW3, for which I had the Root and Alternate switched on interfaces G0/1 and G0/2 on SW3 switched around. When I made the determination that G0/1 on SW3 was root, I did so because of its interface number being lower than G0/2, but I don't understand why I got this wrong, as it was the only difference I saw between G0/1 and G0/2 on SW3 that would have made the determination for the root?
01:00 am at night I was doing this video having on my Krakens. My wife was sleeping in the next room. I was looking for the last question: and I was like: It is Port fast. Port fast. And my wife came up: „Okay, ok.“ We hear you, its c portfast. »Let me sleep.« I just need to make practice on Root selection, if its designated or root etc. Thanks Jeremy
Hey bud, your videos are excellent and beyond depth than any instructor. Keep up the good work! I would be happy to even buy course if you go for CCNP videos :) Also,I need to ask tool that you use for diagrams in your video. Can you share name please?
hello from jordan jeremy thanks alot for these videos i am starting understanding ccna much better than i took it that corse in my country gad blessed you i hope
I love very much that course, i am learning step by step, but i am learning very well because Jeremy teaches very good, is very easy to learn with him.
thank you a lot for this explanation, you realy know how to introduce the informations. I'm looking forward to take ccna exam after finish your course. I also use CCNA 200-301 Official Cert Guide, volume 1 and 2. I hope that it is enough to can pass the exam.
38:05 -- Does anyone know why SW2 G0/1 has a lower root cost than SW4's G0/1? I thought SW4's G0/1 would have a root cost of 8 toward the root bridge, while SW2's G0/1 root cost to the root bridge would be 12? Do you go downwards, left, then Up versus G0/1 SW4's G0/1 going upwards and then left to the root bridge?
Probably you already figured this out, but the root cost is related to the whole device and not to a single interface. So SW2's root cost is 4 no matter what which of its interfaces you are taking into consideration
Great stuff i got the quiz questions right and understand. Cant wait till you finish the course ill miss ya when im studying vol 2 via textbook. Monetary support incoming
thank you soooo much jeremy, youre such a great guy! really appreciate your hard work. you didnt record all the other parts yet, didnt you? i would pay for them to get them earlier to finish your course as fast as possible as i have some free time now
I second that, I have purchased the Neil Anderson's course on Udemy and it doesn't compare to Jeremy's IT lab. I had to purchase it because I want to finish the course earlier and take the exam. If Jeremy would finish the course earlier than the end of the year (even if he makes it a paid course) I would definitely buy it without a second thought.
@@JeremysITLab ok thanks :) I have a question, do you think you already made the most difficult topics on ccna till now? Or are there topics remaining which aren't easy to understand? So I can compare if its worth taking another course for the rest you didn't made yet
Hi, thank you all for the work that has been done for the CCNA . I have a small question regarding the Question 4 RSTP quizz : Why SW3 took G0/2 as a root port even though it has G0/1 which has lower port ID ? (Since the cost is the same) Same with SW4 : Why does he take g0/0 as root port even though the cost doesn't add and SW2 has lower mac The other for me stp is : - Root bridge (prio then MAC) - Port role (Cost then Brigde ID (Prio then MAC) - PID What do I do wrong if someone can explain me, I would be very grateful
Hi! I'll give some quick answers to your questions: 1) SW3 selected G0/2 because it is connected to a lower port ID on SW1. Remember, it's the neighbor port ID, not the port ID on this device, that is important. SW3 G0/1 is connected to SW1 G0/2. SW3 G0/2 is connected to SW1 G0/1 (lower port ID) 2) SW4 selected G0/0 as its root port because it has the same root cost via SW2 and SW3, but SW3 has a lower bridge ID (lower priority: 8193 vs 32769).
Ahhh okay thanks a lot, I was doing the local PID not the neighbour PID thanks a lot that helped a lot. Planning to get the exam around December still some work to do
I have few doubts about the explanation about BackboneFast's example. I will write my thought process. Keep in mind that I refer to Link1=SW1-SW3, Link2=SW1-SW2, Link3=SW2-SW3. My principle problem is that if we cut off the link L1, SW1 continues to send Hello BPDUs every 2 seconds to SW2, then SW2 would keep resetting its max age timer, and it would not age out. If SW1 were still active and sending these BPDUs, SW2 would continue to receive them and keep its port states in alignment with SW1 as the root bridge, without any need for reconvergence. The confusion here stems from a subtlety in the scenario: for SW2’s max age timer to expire, the assumption is that the original root bridge SW1 is no longer able to communicate with SW2. This means that when link L1 goes down, it effectively isolates SW1 from the rest of the network, stopping it from sending Hello BPDUs to SW2. BUT in a typical network setup, the failure of link L1 between SW1 and SW3 would not prevent SW1 from continuing to send BPDUs to SW2 directly, assuming there is a functioning link L2 between SW1 and SW2. STP would normally rely on this redundancy to maintain continuity without requiring reconvergence: 1. L1 Failure with L2 Intact: If only link L1 fails, SW1 would still send Hello BPDUs to SW2 over L2 every 2 seconds. Since SW2 continues to receive these BPDUs, it will reset its max age timer with each BPDU received from SW1. Thus, the BPDU from SW1 remains active in SW2’s memory, and SW2 does not age out this BPDU. This means that SW2 will ignore SW3’s BPDUs and will not need to transition its blocked port to the listening or forwarding states. The network remains stable with SW1 as the root bridge. 2. Impact on SW3: Since SW3 is no longer receiving BPDUs from SW1 (due to the L1 failure), SW3 might initially think that the root bridge is unreachable and may start sending BPDUs claiming itself as the new root. However, because SW2 continues to receive superior BPDUs from SW1, it ignores SW3's BPDUs. This prevents any STP topology changes from occurring. 3. No Need for Max Age Expiry or Port State Changes: Because SW2 keeps receiving valid BPDUs from SW1, it does not enter a state where the max age timer expires, and no port state transitions are necessary. The network maintains connectivity with SW1 as the root bridge, and only the path between SW1 and SW3 is affected by the link failure. NOW, enabling the BackboneFast feature on switch SW2 would help prevent the isolation of switch SW3 in this scenario. BackboneFast is specifically designed to accelerate the STP convergence process in response to an indirect link failure, which is exactly what happens here when link L1 fails: - With BackboneFast enabled, SW2 recognizes this BPDU discrepancy as a signal of an indirect link failure (since SW2 still has a direct path to SW1 through L2). Instead of waiting for the max age timer to expire (20 seconds) to age out the old BPDU from SW1, BackboneFast enables SW2 to immediately query SW1 to verify if it is still the root bridge. - SW2 sends a Root Link Query (RLQ) to confirm SW1’s status as the root. When SW1 responds, SW2 immediately learns that SW1 is indeed still active and retains its role as the root bridge. - Because SW2 quickly reaffirms SW1 as the root, it can ignore SW3's claims without waiting for the max age timer to expire. This ensures that the topology remains stable, now changing the port on SW2 with minimal delay, and without allowing SW3 to incorrectly isolate itself due to the loss of the link L1.
When determining the Root Port for a switch, do we consider the Root Cost of the switches individual outgoing interface? Or the Root Cost of the entire path to the Root Bridge that interface would take? Same with step 3 "interface on switch with lowest root cost"...do we consider the entire path to the Root Bridge or simply find the one interface on the switch that has the lowest Root Cost out of all interfaces connected to another switch?
Root cost is the root port's root cost. The root cost of other interfaces is only considered when deciding which will be the root port. In either case, its the total cumulative cost to the root, not the just cost value of that single interface (if that were the case, in almost all cases all interfaces on each switch would have the same cost).
@@JeremysITLab what do yo advise to not forget all this details when you’re ahead like in future chapters because sometimes i feel I kind of forgot some details as weeks pass over need some mechanism to better retain information in my brain,.
I didn't understand RSTP Quiz 1. Why did you choose G0/0 as Alternate and G0/1 as Backup port? Yes, I know, higher port id is chosen as backup but I have some missing parts I don't quite get. Could you briefly explain the connection of SW3-SW4 interface port selection again? Selection of D, B and A ports in-between. Thank you beforehand. xo
at 20:51, SW4 G0/0 receives a superior BPDU from a different switch, so it's an alternate switch. Didn't get this sentence. We could choose this port as designated as well, no? Alternate is for when root port fails, one it transfers itself to a root port. But we didn't do it in SW2. SW2 has one designated and one root port, no alternate to back it up. Help would be appreciated drastically.
Sorry I'm not going to go through all of your questions now, but I recommend re-watching my earlier STP videos (Days 20 and 21) as well as the earlier parts in this video where I introduce Alternate and Backup ports, your questions are answered there.
Hi I would like to thank you for your CCNA videos and also the labs that you have provided for us to practice it's been really helpful, I was wondering can you make a video regarding WAN concepts and technologies and also QoS thank you very much.
Hi, Very good material for CCNA Cannot find information about validity of the boson NetSim software. Does anyone know what is the validity of the NetSim for Cisco 200-301 CCNA software ($149) ? Is the software one time purchase ?
Hi Jeremy, a couple of points (only to add my humble input to the amazing videos you made). 1. Erratas should be permanently at the top of the comments. I've seen that in other videos but not on this one. 2. The RSTP costing drove me crazy... my Packet Tracer show the STP costings but I was using RSTP !... so I check on a GNS3 with real Cisco image, and the same STP costings !!??... then I found that there is a setting for 32 bit (instead of 16 bit) costing and that is how the switch shows the RSTP costing... I have not read all comments, perhaps this was already mentioned.
your teaching style is very attractive. we will be very glad if you give tutorial about following subject 6.0 Automation and Programmability 6.1 Explain how automation impacts network management 6.2 Compare traditional networks with controller-based networking 6.3 Describe controller-based and software defined architectures (overlay, underlay, and fabric) 6.3.a Separation of control plane and data plane 6.3.b North-bound and south-bound APIs 6.4 Compare traditional campus device management with Cisco DNA Center enabled device management 6.5 Describe characteristics of REST-based APIs (CRUD, HTTP verbs, and data encoding) 6.6 Recognize the capabilities of configuration management mechanisms Puppet, Chef, and Ansible 6.7 Interpret JSON encoded data
Crystal clear explanation as always, thank you so much! Btw, I was wondering if you already have the whole course contents layout, could you share it with us? That would be great. I really like how you did it, from OSI to subnetting, static routing, VLSM, VLAN, DTP/VTP, STP, etc. Other courses that I took before are different where it goes from OSI, subnetting to TCP/UDP, DHCP, NAT, etc. More theories than actually creating and working with networks. Having the course roadmap will allow us to study on our own while waiting for the next upload. What do you think?
I don't have the exact order mapped out, I just know the general direction. I can tell you the next few topics though: EtherChannel, dynamic routing protocols (OSPF), first-hop redundancy protocols.
jeremy, how a port is selected for the backup port--> what does it mean that the superior BPDU is recieved from the same switch, i mean we have to check for the bridge with lower bridge id and that bridge will be having the remaining port as the backup port , right?
'Superior' means 'better from the perspective of the STP process'. If the switch is the same, that means the bridge ID is the same. So, we're comparing the port priority and port ID.
When will Cisco create Super Mega Meta PVST++ in response to the IEEE? lol. Ignore the following, they've all been addressed in an "errata" comment already: Also, a trivial mistake at 16:01: "made age timers" vs. "max age timers". Yet another: SW1 has two G0/0 interfaces at 38:50. I'm probably the one in the wrong on this last one, but don't SW3's /1 & /2 interfaces have their roles swapped in the same quiz question's answer? The lower port ID receives the root port role, correct?
Hello Jeremy & Thanks for all of your high quality work. I've a question please. In 20:26 you mentioned that SW3's G0/0 will be the DP because it has the lowest Port ID. However in Day 20 Part 1 : we saw only 2 conditions for DP selection : 1) The switch with lowest Root cost : it is the case for SW3 2) The interface on switch with lowest Bridge ID : both G0/0 and G0/1 fulfill this condition and they have the same Bridge ID (they are in the same switch). so how G0/0 will be the DP in this segment ?
At the time 38:29 why was G0/2 on switch3 selected as the Root port? and Alternate port was G0/1? Would it not be the other way around? G0/1 has a lower priority from Sw1. I probably have missed something, thank you for your clarifaction in advance.
Hello Jeremy, Loving the course so far. I am learning a lot, and I have one question for Quiz 4. Why did switch 3 select g0/2 to be its root bridge. Does the tie breaker go the the sender's port ID or the receivers bridge ID or am I mistaken in believing that g0/2 port ID is higher than g0/1. Thank you.
Hi Jeremy, Thanks for your Awesome CCNA videos. Do you have videos on BGP. Please share the Link or name of the videos. Searched for them, but didn't get.
Hi Jeremy, Quiz-4 (37.59) If switches 2 and 3 are the same priority, is that Switch 4 interface G0/1 would become a root port instant of G0/0?( but it did not change.) "show spanning-tree" of sw2 still shows share type cost is 19, even if I change to a root bridge. So hub makes difference?
If you're trying this in packet tracer, the hub doesn't work correctly sometimes. You are correct that SW4 G0/1 would be the root port if SW2 and SW3 have the same priority.
Hi Jeremy and thanks for your great video. G0/1 was chosen on sw2 to be the designated port because of the lower root cost. But was also chosen because it has the lower port id compare to g0/2, which has the same root cost has g0/1. Is that correct?
Hi Jeremy, using your diagram for Quiz 4 (37:39). Lets say for example if SW2 was designated as the root bridge by lowering the bridge priority. What would then happen to G0/1 and G0/2? Will both of them still be designated ports (Since all ports on root bridges are designated) or would G0/2 become an alternate port?
Hey Jeremy! Do we have to know the process of the handshake mechanism (proposal / agreement) that switches use to negotiate, for the exam or it's above the level of CCNA?
I can't make any guarantees, but I highly doubt you'll get any questions about that on the CCNA. At the CCNP level, definitely you should know it, but at the CCNA level I wouldn't bother. No harm in learning it of course, but I don't think it's necessary.
Hey Jeremy! Got some questions about hubs : - Can they be used with another cable than Fast Ethernet? (Can they even be used with FastEthernet cable? I've read that the maximum speed of a hub interface is 10 Mbps) - If so, what happens when you connect FastEthernet cable on one side and Ethernet cable on the other side? what will be the root cost of a path like that?
for a port to change from blocking to forwarding it would take 50s in classic (20s for max age, and 30s for forward delay timer) how long it takes for rapid stp? it did not cleary say it in the video
Hi Jeremy, Thanks for the awesome lesson! Do you need to set up bpdu guard on the edge link in RSTP also? If you do, is it done in the same way as STP? Thanks for the help.
Hi Jeremy! In classic STP, I believe you said that BPDUs are only forwarded by designated ports. Therefore, can I correctly assume that in RSTP, where *all* switches originate BPDUs (not just the root bridge), this rule does not apply and BPDUs will be forwarded via other ports as well?
Hi Jeremy, thanks for these videos. I just want to clarify something I'm not quite sure about. In Spanning Tree topology on the quiz, are the blocking (back up) ports, back up ports because having a higher port id, they send (as opposed to receive) a superior BDPU from the same switch? I don't see how SW2's G0/2 could possibly receive a superior BPDU from SW4 seeing as the Root Bridge is SW1 connected to SW2's G0/0. That is to say the superior BPDU is received by SW2 on its G0/0 interface and advertised out G0/1 and G0/2 (the latter G0/2 ending up in a backup state as opposed to G0/1 that is designated with a lower port id). I have the same question for quiz 1 in this video (20:40) where SW3's G0/1 is in a back up state with the only apparent explanation being because it sent (as opposed to received) a superior BPDU on its G0/1 interface. Thanks again, most especially for clarifying if you can. Cheers!
We're deciding which of the interfaces of that connection sends the superior BPDU. SW2 G0/1 vs SW2 G0/2 vs SW4 G0/1. SW2's interfaces are superior to SW4's (due to root cost), and G0/1 has a lower port ID than G0/2 so G0/1 sends the superior BPDU. G0/2 becomes Backup because it receives a superior BPDU from a port on the same switch (SW2 G0/1) as opposed to from another switch (SW4 G0/1).
In 38:14 : What video should I review to understand "Why was an interface on SW2 and not SW4 selected to be a Designated port?". In my though, I would think except Root port everyone else is Designated port? I still don't understand why SW2 G0/2 and SW4 G0/1 not Designated port.
After 5 hours to watch video Day 20. I think : SW2 G0/1 is Desginated port. Why it not SW2 G0/2 or SW4 G0/1 ? Because SW2 G0/1 has a lowest root cost and lowest Prior.Nbr than SW2 G0/2. (128.2 < 128.3) Someone please confirm for me.
HI Jeremy, thank you for that excellent course. I cant understand the difference between PortFast feature and Uplink feature , I understand that Portfast is a feature that I can use for access ports or ports that connect switches to Endhost ,,but also I can use it for trunk ports !!,so what it is the difference between these two features. and another question ,we need the forward delay to prevent layer2 loops ,so why we are skipping that time by using Uplink feature , aren't we put the network in a danger when we doing that? thank you very much Jeremy 🖤🖤🖤
ERRATA:
Typo at 16:00: “BackboneFast allows SW3 to expire the *made* age timers...” should be ”expire the *max* age timers...”
At 37:15, SW1's port connected to the PC should be G0/3, not G0/0.
Don't you think, that SW3's G0/1 should be the root port and not G0/2? They have same root cost, same neighbour BPDU, but G0/1 has lower port ID giving it advantage to become root over G0/2
@@sidmahajan1632 What time in the video?
@@JeremysITLab @Jeremy's IT Lab 37:55
@@sidmahajan1632 Review this part of Day 20's video, that'll give you the answer: ruclips.net/video/j-bK-EFt9cY/видео.html
@@JeremysITLab Oh wow!! i didn't knew that, that makes a lot of sense now. Thanks Jeremy for the reply and info, you are the best.
There is on one side courses/books that briefly tell you about some concepts, tell you what to remember and give definitions to learn by heart, making it really boring, and on the other side Jeremy's lessons that make you really understand all these concepts in detail and making it interesting at the same time!
Can you believe that the Official Cert Guide Library from Cisco Press is not even mentioning non-designated ports, not talking about which port roles send/receive BPDUs, and, what I consider the worst: giving extremely poor explanations about path costs, alternate ports, and backup ports (they are just mentioned)?
Thank you, for real, for all this time you invested in us, making it so interesting!
I've noticed Jeremy likes to explain things in more detail than is necessary for the CCNA. This is actually a good thing in my opinion because the extra detail helps me remember concepts better than someone saying "this is the way it is just because it is". With that in mind, if you retain everything from the official cert guide, its plenty to get an excellent score on the exam, it's just not necessarily easy to do that when the content is so dry and poorly explained.
Jeremy, i have taken 3 times CCNA courses since version 4.0. but you are by far the best teacher. Really clear concepts and great methodology and examples. Really, thank you for sharing your knowledge and effort on this course.I hope you can finish all the topics!
Thank you Jorge :)
Hi Jeremy. I started to read the official documentation for CCNA, before knowing about this course, but I didn't understand 100% the STP. I was a bit frustrated, but then I discovered your course. I am really happy, you are a great teacher and explain the topics in a simple way that it's easy to understand. Now, I first watch your video and practice with labs and then I read the official documentation. It changed my world. Thanks so much for this course !!!
Thank you Francesco, I'm glad my videos helped you understand!
Least we can do. Please do not forget to like all the videos
Been liking since #1
I had already done the CBT Nuggets videos and read Todd Lammle books which are all great, but left me a little iffy on some concepts, after watching your videos I am finally understanding everything that I missed or was unsure about! Thank you so much, I was about to give up after not understanding it well from those other two sources.
Although you said that you don't have to much time for the videos, keep it going to make the rest of the videos early, you are such a good teacher.
I'm studying CCNA from your videos.
Thank you! I'll do my best.
I gotta say, you def. made this easier by teaching us the parts of STP that may not be on the exam, too. I found myself struggling to grasp Classic STP for a few days. But after some studying + the flashcards and lab, I mostly got it down. Now, learning RSTP feels like a breeze. That's "wax on, wax off" type stuff. Markings of a GREAT teacher. 😄
Thanks!
Thanks so much for the tip! Sorry for the late reply, I just noticed this comment now. I appreciate your support :)
Thank you so much for this...i love the labs and I know the more I do them, the better off I'll be...I'm learning a lot with the labs and that's something that distinguishes between this channel and others. Keep up the great work!!!!
Thanks Alina!
Hello from Russia, Jeremy) Thank you for your incredible help in preparing for the CCNA)
Hello! Спасибо! :)
Hi snake
I was having some confusion with the RSTP and after having watched your video, everything became crystal clear.. great video and very well implemented with examples at the right time plus the Boson exam sim is a great bonus.. Can't thank you enough.. looking forward to your next CCNA videos.. cheers!
Dear Jeremy,
Please forgive me for not watching your videos for a while now. I've been using the Boson Simlab for practice and have not be in on RUclips. You're still awesome.
Your friend you've never met,
Timmy Tim McTimson
No worries, watch at your own pace ;) Glad you like them!
The thorough job you`ve done for this series of videos is just insane. Great explanation as always. Thank you for this
Just completed the lectures, excited to work on the labs then practices tests! Great work putting this together!
Well done! Just a heads up, the course isn't finished yet, I've only covered about 50% of the topics!
I must be Rapid SPT myself, because I'm basically in a "Blocking, Listening and Disabled states are combined, and the Listening state is not used" state every day at work.
More motivation for me to study and pass CCNA in hopes of landing a better job.
If not for Jeremy I'd probably have given up already.
All of your contents were very informative and in detail that I have ever watched. Thank you very much for sharing your great knowledge for free
Thank you :)
After I had watched your STP 1, 2 and this one, I really felt regret for missing your channel to watch and learn from you. Thanks a lot for your kind contribution. with Best Regards,
Another excellent video. Thank you. I especially benefited from quiz question 4 and your subsequent detailed explanation. I appreciate the work you put into these questions.
Wow, me getting the RSTP Quiz 4 question right was satisfying. Adding hubs into the mix really trips me up, but I am proud I got it right :) And it's all thanks to you, Jeremy. Thank you so much.
I got Quiz 4 wrong the first time then watched the entire video again with playback speed 1.5x and then finally understood how to assign the port roles properly, thank you!
So my network diagram I made was ALMOST exactly as shown at 38:45 with one exception: the G0/1 link on SW1 connecting to G0/2 on SW3, for which I had the Root and Alternate switched on interfaces G0/1 and G0/2 on SW3 switched around. When I made the determination that G0/1 on SW3 was root, I did so because of its interface number being lower than G0/2, but I don't understand why I got this wrong, as it was the only difference I saw between G0/1 and G0/2 on SW3 that would have made the determination for the root?
always with you, jeremy
Hello from Philippines. You have a chance to change people life's by doing this free CCNA. Maraming Salamat
Thank you! 🇵🇭
from kenya am self teaching and all is well @ day 22 .bless you jeremy!
01:00 am at night I was doing this video having on my Krakens. My wife was sleeping in the next room. I was looking for the last question: and I was like: It is Port fast. Port fast. And my wife came up: „Okay, ok.“ We hear you, its c portfast. »Let me sleep.«
I just need to make practice on Root selection, if its designated or root etc. Thanks Jeremy
Hey bud, your videos are excellent and beyond depth than any instructor. Keep up the good work! I would be happy to even buy course if you go for CCNP videos :) Also,I need to ask tool that you use for diagrams in your video. Can you share name please?
I just use LibreOffice Impress, which is basically a free version of powerpoint. If you have powerpoint, that's just as good :)
Eyyyy I finally Finished The Video with full understanding .... thank you :D
Nice ;)
me to :)
hello from jordan jeremy thanks alot for these videos i am starting understanding ccna much better than i took it that corse in my country gad blessed you i hope
I love very much that course, i am learning step by step, but i am learning very well because Jeremy teaches very good, is very easy to learn with him.
thank you a lot for this explanation, you realy know how to introduce the informations. I'm looking forward to take ccna exam after finish your course. I also use CCNA 200-301 Official Cert Guide, volume 1 and 2. I hope that it is enough to can pass the exam.
With my videos and those books, you'll definitely be able to pass!
@@JeremysITLab thanks again you gave me another push and more confident
Thank you Jeremy. Your videos are awesome and very informative!!!
Thank you!
It took me some time to understand this, but is so clear now. i had concept maps of this.
Keep it up!!! I am planning to take the ccna exam after this quarantine
Good luck! Let me know your result after you take it.
me too. you are my first teacher of ccna and i learned a lot from you. thank you so much for your teaching sir, Jeremy.
I hope you did well on the test
Hey J! This video is awesome, very didactic. My best wishes for you. From Amazonia, but now I live in Portugal.
Thank you, glad you like it!
38:05 -- Does anyone know why SW2 G0/1 has a lower root cost than SW4's G0/1? I thought SW4's G0/1 would have a root cost of 8 toward the root bridge, while SW2's G0/1 root cost to the root bridge would be 12? Do you go downwards, left, then Up versus G0/1 SW4's G0/1 going upwards and then left to the root bridge?
Probably you already figured this out, but the root cost is related to the whole device and not to a single interface. So SW2's root cost is 4 no matter what which of its interfaces you are taking into consideration
Such a great explanation.. I always waiting for the next video.
Thank you!
Great stuff i got the quiz questions right and understand. Cant wait till you finish the course ill miss ya when im studying vol 2 via textbook. Monetary support incoming
Thanks Jeremy! Glad you're liking the course ;)
Hi Jeremy. Thanks for the awesome videos. You have a great teaching style. How many videos are you planning on making for this series?
I think it will be about 50 days in total, so 90 to 100 videos.
very good lecture, thorough, clear, especially quiz questions are very helpful
Finally feel to be able to get out the long, dark STP tunnel to move forward,Thank you very much.
Finally i managed to solve the quiz on my own!!! yeah baby!
Quiz 4 was so good, thanks jeremy!
Minute 2:27 "it was created in 1985" why does the doc from Back to the future come to my mind now?👀☝️... Thanks Jeremy! Bonjour du Mexique !👍🏻👍🏻👏👏🇲🇽🇲🇽
Thansk Renato ;)
Jeremy you are a legend, Im picking this all up. Thanks
Brilliant session, very clear and easy to be understood.
Thanks so much Jeremy :)
Great videos, I am currently taking CCNA2, your videos are a great addition to my course.
I recommend Jeremy it lab as it provides best quality Cisco training material
Thank you! I'm glad :)
Great job Jeremy, keep up the good work.
thank you soooo much jeremy, youre such a great guy! really appreciate your hard work. you didnt record all the other parts yet, didnt you? i would pay for them to get them earlier to finish your course as fast as possible as i have some free time now
I second that, I have purchased the Neil Anderson's course on Udemy and it doesn't compare to Jeremy's IT lab. I had to purchase it because I want to finish the course earlier and take the exam. If Jeremy would finish the course earlier than the end of the year (even if he makes it a paid course) I would definitely buy it without a second thought.
@@abdelrahmanelsherbiny8833 you already passed your exam?
@@MM-bm7wt No I am still studying, got half way through and I plan to take the exam in a month or so.
Sorry, I don't! Making these videos isn't my job so I don't have a lot of spare time to make them.
@@JeremysITLab ok thanks :) I have a question, do you think you already made the most difficult topics on ccna till now? Or are there topics remaining which aren't easy to understand? So I can compare if its worth taking another course for the rest you didn't made yet
Watched the videos on stp topic 3 times 😀
Thanks Jeremy👍
Thank you so much for this course!
My pleasure!
Hi, thank you all for the work that has been done for the CCNA .
I have a small question regarding the
Question 4 RSTP quizz :
Why SW3 took G0/2 as a root port even though it has G0/1 which has lower port ID ? (Since the cost is the same)
Same with SW4 : Why does he take g0/0 as root port even though the cost doesn't add and SW2 has lower mac
The other for me stp is :
- Root bridge (prio then MAC)
- Port role
(Cost then Brigde ID (Prio then MAC)
- PID
What do I do wrong if someone can explain me, I would be very grateful
Hi! I'll give some quick answers to your questions:
1) SW3 selected G0/2 because it is connected to a lower port ID on SW1. Remember, it's the neighbor port ID, not the port ID on this device, that is important.
SW3 G0/1 is connected to SW1 G0/2.
SW3 G0/2 is connected to SW1 G0/1 (lower port ID)
2) SW4 selected G0/0 as its root port because it has the same root cost via SW2 and SW3, but SW3 has a lower bridge ID (lower priority: 8193 vs 32769).
Ahhh okay thanks a lot, I was doing the local PID not the neighbour PID thanks a lot that helped a lot.
Planning to get the exam around December still some work to do
I have few doubts about the explanation about BackboneFast's example. I will write my thought process. Keep in mind that I refer to Link1=SW1-SW3, Link2=SW1-SW2, Link3=SW2-SW3.
My principle problem is that if we cut off the link L1, SW1 continues to send Hello BPDUs every 2 seconds to SW2, then SW2 would keep resetting its max age timer, and it would not age out. If SW1 were still active and sending these BPDUs, SW2 would continue to receive them and keep its port states in alignment with SW1 as the root bridge, without any need for reconvergence.
The confusion here stems from a subtlety in the scenario: for SW2’s max age timer to expire, the assumption is that the original root bridge SW1 is no longer able to communicate with SW2. This means that when link L1 goes down, it effectively isolates SW1 from the rest of the network, stopping it from sending Hello BPDUs to SW2.
BUT in a typical network setup, the failure of link L1 between SW1 and SW3 would not prevent SW1 from continuing to send BPDUs to SW2 directly, assuming there is a functioning link L2 between SW1 and SW2. STP would normally rely on this redundancy to maintain continuity without requiring reconvergence:
1. L1 Failure with L2 Intact: If only link L1 fails, SW1 would still send Hello BPDUs to SW2 over L2 every 2 seconds. Since SW2 continues to receive these BPDUs, it will reset its max age timer with each BPDU received from SW1. Thus, the BPDU from SW1 remains active in SW2’s memory, and SW2 does not age out this BPDU. This means that SW2 will ignore SW3’s BPDUs and will not need to transition its blocked port to the listening or forwarding states. The network remains stable with SW1 as the root bridge.
2. Impact on SW3: Since SW3 is no longer receiving BPDUs from SW1 (due to the L1 failure), SW3 might initially think that the root bridge is unreachable and may start sending BPDUs claiming itself as the new root. However, because SW2 continues to receive superior BPDUs from SW1, it ignores SW3's BPDUs. This prevents any STP topology changes from occurring.
3. No Need for Max Age Expiry or Port State Changes: Because SW2 keeps receiving valid BPDUs from SW1, it does not enter a state where the max age timer expires, and no port state transitions are necessary. The network maintains connectivity with SW1 as the root bridge, and only the path between SW1 and SW3 is affected by the link failure.
NOW, enabling the BackboneFast feature on switch SW2 would help prevent the isolation of switch SW3 in this scenario. BackboneFast is specifically designed to accelerate the STP convergence process in response to an indirect link failure, which is exactly what happens here when link L1 fails:
- With BackboneFast enabled, SW2 recognizes this BPDU discrepancy as a signal of an indirect link failure (since SW2 still has a direct path to SW1 through L2). Instead of waiting for the max age timer to expire (20 seconds) to age out the old BPDU from SW1, BackboneFast enables SW2 to immediately query SW1 to verify if it is still the root bridge.
- SW2 sends a Root Link Query (RLQ) to confirm SW1’s status as the root. When SW1 responds, SW2 immediately learns that SW1 is indeed still active and retains its role as the root bridge.
- Because SW2 quickly reaffirms SW1 as the root, it can ignore SW3's claims without waiting for the max age timer to expire. This ensures that the topology remains stable, now changing the port on SW2 with minimal delay, and without allowing SW3 to incorrectly isolate itself due to the loss of the link L1.
When determining the Root Port for a switch, do we consider the Root Cost of the switches individual outgoing interface? Or the Root Cost of the entire path to the Root Bridge that interface would take? Same with step 3 "interface on switch with lowest root cost"...do we consider the entire path to the Root Bridge or simply find the one interface on the switch that has the lowest Root Cost out of all interfaces connected to another switch?
Root cost is the root port's root cost. The root cost of other interfaces is only considered when deciding which will be the root port. In either case, its the total cumulative cost to the root, not the just cost value of that single interface (if that were the case, in almost all cases all interfaces on each switch would have the same cost).
Jeremy, what abot learning state in RSTP+? Never mentioned it.
Thanks a lot Sir for your efforts, when often you publish new videos for the series ?
I publish a new video every week!
A long video but very informative. thanks again
Agreed. STP is wearing on me.
16:53
maybe we should be allowed to use google on the test lol
That's a lot of info to digest. Thanks, Jeremy
Yes it is! Take your time to absorb it all, no rush.
@@JeremysITLab what do yo advise to not forget all this details when you’re ahead like in future chapters because sometimes i feel I kind of forgot some details as weeks pass over need some mechanism to better retain information in my brain,.
Sadly I'll take my exam before you finish the course but I am enjoying it so far.
Thanks, glad to hear that :)
So nicely prepared.
I didn't understand RSTP Quiz 1. Why did you choose G0/0 as Alternate and G0/1 as Backup port? Yes, I know, higher port id is chosen as backup but I have some missing parts I don't quite get. Could you briefly explain the connection of SW3-SW4 interface port selection again? Selection of D, B and A ports in-between. Thank you beforehand. xo
at 20:23, you said SW3 has lower cost, so one of its interfaces will be designated port. What does this sentence mean?
at 20:51, SW4 G0/0 receives a superior BPDU from a different switch, so it's an alternate switch. Didn't get this sentence. We could choose this port as designated as well, no? Alternate is for when root port fails, one it transfers itself to a root port. But we didn't do it in SW2. SW2 has one designated and one root port, no alternate to back it up. Help would be appreciated drastically.
Sorry I'm not going to go through all of your questions now, but I recommend re-watching my earlier STP videos (Days 20 and 21) as well as the earlier parts in this video where I introduce Alternate and Backup ports, your questions are answered there.
Finally, I'm in day 22
Alhamdulilah
Thanks jeremmy.
May Allah reward you to the paradise.
Hey Sir, I found your explaination the best in youtube and i have went through all of yours CCNA series . May i ask do u have series for CCNP?
Hi I would like to thank you for your CCNA videos and also the labs that you have provided for us to practice it's been really helpful, I was wondering can you make a video regarding WAN concepts and technologies and also QoS thank you very much.
Thank you! I'll cover those topics later in the course.
Hi,
Very good material for CCNA
Cannot find information about validity of the boson NetSim software. Does anyone know what is the validity of the NetSim for Cisco 200-301 CCNA software ($149) ? Is the software one time purchase ?
Hi Dharmik. It's a one-time purchase
Hi Jeremy, a couple of points (only to add my humble input to the amazing videos you made).
1. Erratas should be permanently at the top of the comments. I've seen that in other videos but not on this one.
2. The RSTP costing drove me crazy... my Packet Tracer show the STP costings but I was using RSTP !... so I check on a GNS3 with real Cisco image, and the same STP costings !!??... then I found that there is a setting for 32 bit (instead of 16 bit) costing and that is how the switch shows the RSTP costing... I have not read all comments, perhaps this was already mentioned.
your teaching style is very attractive. we will be very glad if you give tutorial about following subject
6.0 Automation and Programmability
6.1 Explain how automation impacts network management
6.2 Compare traditional networks with controller-based networking
6.3 Describe controller-based and software defined architectures (overlay, underlay, and fabric)
6.3.a Separation of control plane and data plane
6.3.b North-bound and south-bound APIs
6.4 Compare traditional campus device management with Cisco DNA Center enabled device management
6.5 Describe characteristics of REST-based APIs (CRUD, HTTP verbs, and data encoding)
6.6 Recognize the capabilities of configuration management mechanisms Puppet, Chef, and Ansible
6.7 Interpret JSON encoded data
Thank you! This will be a complete course for the CCNA, so I will cover those topics later.
Crystal clear explanation as always, thank you so much!
Btw, I was wondering if you already have the whole course contents layout, could you share it with us? That would be great.
I really like how you did it, from OSI to subnetting, static routing, VLSM, VLAN, DTP/VTP, STP, etc. Other courses that I took before are different where it goes from OSI, subnetting to TCP/UDP, DHCP, NAT, etc. More theories than actually creating and working with networks.
Having the course roadmap will allow us to study on our own while waiting for the next upload. What do you think?
I don't have the exact order mapped out, I just know the general direction. I can tell you the next few topics though: EtherChannel, dynamic routing protocols (OSPF), first-hop redundancy protocols.
Excellent Jeremy! Thank you!
Thanks Neil!
Thank you very much for the videos. I complete the quiz 4 without mistakes :)
THANK YOU VERY MUCH SIR ITS REALLY HELP ME LEARNING THIS SUBJECT
Thanks for watching ;)
jeremy, how a port is selected for the backup port--> what does it mean that the superior BPDU is recieved from the same switch, i mean we have to check for the bridge with lower bridge id and that bridge will be having the remaining port as the backup port , right?
'Superior' means 'better from the perspective of the STP process'. If the switch is the same, that means the bridge ID is the same. So, we're comparing the port priority and port ID.
When will Cisco create Super Mega Meta PVST++ in response to the IEEE? lol.
Ignore the following, they've all been addressed in an "errata" comment already:
Also, a trivial mistake at 16:01: "made age timers" vs. "max age timers".
Yet another: SW1 has two G0/0 interfaces at 38:50.
I'm probably the one in the wrong on this last one, but don't SW3's /1 & /2 interfaces have their roles swapped in the same quiz question's answer? The lower port ID receives the root port role, correct?
Hello Jeremy & Thanks for all of your high quality work.
I've a question please. In 20:26 you mentioned that SW3's G0/0 will be the DP because it has the lowest Port ID.
However in Day 20 Part 1 : we saw only 2 conditions for DP selection :
1) The switch with lowest Root cost : it is the case for SW3
2) The interface on switch with lowest Bridge ID : both G0/0 and G0/1 fulfill this condition and they have the same Bridge ID (they are in the same switch).
so how G0/0 will be the DP in this segment ?
Dear jeremy thankyou
Thanks for watching :)
11:50 "this was previously the disabled state" - correction: it was the blocking state, because the disabled state discarded BPDUs!
'The 802.1D disabled, blocking, and listening states are merged into a unique 802.1w discarding state.' -Cisco
What I state in the video is correct.
thank you
At the time 38:29 why was G0/2 on switch3 selected as the Root port? and Alternate port was G0/1? Would it not be the other way around? G0/1 has a lower priority from Sw1. I probably have missed something, thank you for your clarifaction in advance.
Hello Jeremy, Loving the course so far. I am learning a lot, and I have one question for Quiz 4. Why did switch 3 select g0/2 to be its root bridge. Does the tie breaker go the the sender's port ID or the receivers bridge ID or am I mistaken in believing that g0/2 port ID is higher than g0/1. Thank you.
Hi Jeremy, Thanks for your Awesome CCNA videos. Do you have videos on BGP. Please share the Link or name of the videos. Searched for them, but didn't get.
Wooow sir awesome teaching technique
Thank you ;)
Hi Jeremy, Quiz-4 (37.59) If switches 2 and 3 are the same priority, is that
Switch 4 interface G0/1 would become a root port instant of G0/0?( but it did not change.) "show spanning-tree" of sw2 still shows share type cost is 19, even if I change to a root bridge. So hub makes difference?
If you're trying this in packet tracer, the hub doesn't work correctly sometimes. You are correct that SW4 G0/1 would be the root port if SW2 and SW3 have the same priority.
@@JeremysITLab Thank you so much.
Sir, you deserve more but I can't do more than a comment, like, share and subscribe!
I mean it...
Thank you again for the course... how many labs are on the exam approx. and how many questions... thanks
No labs, and around 100 questions.
Jeremy, one cuestion: Why G0/1 SW2 is Designated port and no G0/2, both have the same cost. Minute 38:10
G0/1 has a lower port ID
@@JeremysITLab thank you for information.
Hi Jeremy and thanks for your great video. G0/1 was chosen on sw2 to be the designated port because of the lower root cost. But was also chosen because it has the lower port id compare to g0/2, which has the same root cost has g0/1. Is that correct?
Thank u very much sir. i appreciate your work.
Thank you :)
great lecture.
Thank you :)
Hi Jeremy, using your diagram for Quiz 4 (37:39). Lets say for example if SW2 was designated as the root bridge by lowering the bridge priority. What would then happen to G0/1 and G0/2? Will both of them still be designated ports (Since all ports on root bridges are designated) or would G0/2 become an alternate port?
G0/2 would still be a blocking port
@@JeremysITLab Got it thanks!
Hey Jeremy! Do we have to know the process of the handshake mechanism (proposal / agreement) that switches use to negotiate, for the exam or it's above the level of CCNA?
I can't make any guarantees, but I highly doubt you'll get any questions about that on the CCNA. At the CCNP level, definitely you should know it, but at the CCNA level I wouldn't bother. No harm in learning it of course, but I don't think it's necessary.
OK i will have a brief look on it, just to be sure and be ready 100%. Thank you so much and congratulations for your 100K subscribers.
Hey Jeremy!
Got some questions about hubs :
- Can they be used with another cable than Fast Ethernet? (Can they even be used with FastEthernet cable? I've read that the maximum speed of a hub interface is 10 Mbps)
- If so, what happens when you connect FastEthernet cable on one side and Ethernet cable on the other side? what will be the root cost of a path like that?
for a port to change from blocking to forwarding it would take 50s in classic (20s for max age, and 30s for forward delay timer) how long it takes for rapid stp? it did not cleary say it in the video
Hi Jeremy,
Thanks for the awesome lesson!
Do you need to set up bpdu guard on the edge link in RSTP also? If you do, is it done in the same way as STP?
Thanks for the help.
Hi Jeremy! In classic STP, I believe you said that BPDUs are only forwarded by designated ports. Therefore, can I correctly assume that in RSTP, where *all* switches originate BPDUs (not just the root bridge), this rule does not apply and BPDUs will be forwarded via other ports as well?
I don't think so, in RSTP they should be forwarded only out of designated ports too.
Hi Jeremy, thanks for these videos. I just want to clarify something I'm not quite sure about.
In Spanning Tree topology on the quiz, are the blocking (back up) ports, back up ports because having a higher port id, they send (as opposed to receive) a superior BDPU from the same switch? I don't see how SW2's G0/2 could possibly receive a superior BPDU from SW4 seeing as the Root Bridge is SW1 connected to SW2's G0/0. That is to say the superior BPDU is received by SW2 on its G0/0 interface and advertised out G0/1 and G0/2 (the latter G0/2 ending up in a backup state as opposed to G0/1 that is designated with a lower port id). I have the same question for quiz 1 in this video (20:40) where SW3's G0/1 is in a back up state with the only apparent explanation being because it sent (as opposed to received) a superior BPDU on its G0/1 interface.
Thanks again, most especially for clarifying if you can. Cheers!
We're deciding which of the interfaces of that connection sends the superior BPDU. SW2 G0/1 vs SW2 G0/2 vs SW4 G0/1. SW2's interfaces are superior to SW4's (due to root cost), and G0/1 has a lower port ID than G0/2 so G0/1 sends the superior BPDU. G0/2 becomes Backup because it receives a superior BPDU from a port on the same switch (SW2 G0/1) as opposed to from another switch (SW4 G0/1).
In 38:14 : What video should I review to understand "Why was an interface on SW2 and not SW4 selected to be a Designated port?".
In my though, I would think except Root port everyone else is Designated port?
I still don't understand why SW2 G0/2 and SW4 G0/1 not Designated port.
After 5 hours to watch video Day 20. I think :
SW2 G0/1 is Desginated port. Why it not SW2 G0/2 or SW4 G0/1 ?
Because SW2 G0/1 has a lowest root cost and lowest Prior.Nbr than SW2 G0/2. (128.2 < 128.3)
Someone please confirm for me.
@15:36 why does SW3's blocking port become designated? is it because SW2 keeps sending BPDU and this triggers the port to become designated?
I like summarizing things 👌👍☕
HI Jeremy, thank you for that excellent course.
I cant understand the difference between PortFast feature and Uplink feature ,
I understand that Portfast is a feature that I can use for access ports or ports that connect switches to Endhost ,,but also I can use it for trunk ports !!,so what it is the difference between these two features.
and another question ,we need the forward delay to prevent layer2 loops ,so why we are skipping that time by using Uplink feature , aren't we put the network in a danger when we doing that?
thank you very much Jeremy
🖤🖤🖤