NTP Explained | Network Time Protocol | Cisco CCNA 200-301

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NTP stands for Network Time Protocol. It has the very important job of synchronising clocks over a network.
Time is one of those things that can easily be overlooked. In a network though, have inconsistent time, even just by a few minutes, can cause problems.
Every device on a network will have an internal clock. It's important to keep accurate clocks, otherwise, you may run into issues with correlating logs, SSL certificates, software and the list goes on.
This is where NTP comes in. All of the network devices will sync their clocks to an NTP server which will have the accurate time.
NTP uses a hierarchy system. At the very top, we have the big boys, the MacDaddies. These are highly accurate timekeeping devices such as atomic clocks, GPS or radio clocks. They are known as reference clocks.
NTP uses stratum values to identify the accuracy of a clock.
Stratum levels are between 0-15, with 0 being the most accurate and 15 being the least. Anything above 15 means the accuracy of the clock is not trustworthy.
Stratum 0 clocks do not connect over a network.
They are directly connected to time servers. They then sync their time and date to the reference clock. These are known as Primary time servers.
The way the NTP stratum model works is by adding a 1 to stratum value at each layer. So, these primary time servers have a stratum 1 value. As we go further down the stratum hierarchy, the stratum value increases as the reference clock is further and further away meaning the time is less accurate.
NTP uses UDP port number 123. So that’s nice and easy to remember.
#ccna #cisco #networking

[@brianconner1212]

This guy will have a million subscribers soon and he'll stop liking all the comments like how he does now😂😂😂

[@Certbros]

HAHAHa That would be a great problem to have 🤣 I'll try my best not to forget about you when I hit 1M Brian!

[@Loodough]

I was thinking of that too! sorcery 👀😂😂😂

[@quickbf]

I highly doubt that. This video explains nothing about NTP.

[@CaimeoCappucino]

Best explanation of NTP I have ever come across... subscribed!🙂

[@shandeepsamy]

finally i am clear about NTP, thanks a lot

[@Certbros]

Great to hear! Happy to clear it up for you.

[@ogechukwuemedo1882]

Thank you. I like your videos - sharp and straight to the point.

[@Certbros]

Thank you! Glad you liked it.

[@meirrose2347]

A very good and well detailed videos. Thank you

[@Certbros]

Thank you Meir!

[@Sympla40]

Great video, such a clear explanation

[@Certbros]

Thanks Yair!

[@keithfox1323]

Are you planning on making a video about DNS?

[@Certbros]

Yes 100%. The DNS video should be ready in a couple of weeks.

[@rishavpipal4810]

Thanks man , good work 👍

[@IBITZEE]

very good info... ?did you know of any small ntp server for windows... or a 'ntp-proxy' that we can configure to get time from a NIST or equivalent server and serve the internal network??

[@AntoniaRalap]

83837 Witting Mountain

[@ashusvlog1387]

Me an 8th grader watching this for exam 😭😭

[@jemuelbjeroham1228]

Thank you so much for your videos, I have learnt Spanning Tree Protocol from your video only.

[@Certbros]

Thank you Jemuel! You're very welcome. Great to hear your learning from these videos.

[@sajadmohassan]

A joke but xNTP is also an MBTI personality type, it can be introverted or extroverted

[@mry126]

Helpful tip: When he says "Rootah", what he means to say is "Router"

[@tg9460]

Thank you. Very concise and easy to understand tutorial on ntp. Great job.

[@Certbros]

Thanks T G! Really appreciate it.

[@taylorgerrish7264]

rooter

[@PhilemonVic-o5i]

Martin David Harris Barbara Wilson Ruth

[@PradeepKumar-gq8ej]

U r awesome, The way u describe very clear and interesting just awesome. Love from India .

[@Certbros]

Thank you Pradeep! Really appreciate it the support 🙏

[@nurlatifahmohdnor8939]

NAT NCP NFS = Network File System NLP NPU NS NOC NOS NTFS = NT Filesystem NTP

[@rickysaha154]

your videos are too good .. can you just say more about the altenatives of ntp

[@KimberlyRobinson-g6z]

Raynor Center

[@swamysriman7147]

6:05 How does it know the offset of BST?

[@VernonBurton-l4r]

43416 Johns Hills

[@quickbf]

This video explains 0 about NTP. Closest it gets is statement "NTP uses an UDP port 123". I set sync to "pool.ntp.org". What stratum do I get for my PC? How many layers there are? What is a layer? I get 20 node "hops" to "pool.ntp.org", so I get stratum 20? Is that how it works? I am synched and unsynched at one time? Jeez, your video emerges questions, rather than answering one. You show that NTP setup works. We all know that! How does it work? Sends a UDP packet containing what? Receiving what? How is transmission delay corrected? Man, better stop this layman-to-laymen BS spreading. Disliked and got outa here. Shame!

[@aadhargupta4693]

Sir they are doing this for free!!! And it's better to simplify things rather than inserting unnecessary jargons everywhere.

[@jenniferogonda7816]

This is for CCNA and all those details are not needed @Vadim Rodionov.

[@VaughanTony-w3j]

Blanda Parkway

[@OfficiallyOrca]

Simple information yet so cool 😎 Thank you Certbros

[@Certbros]

You're welcome! Glad you liked it.

[@ardentdfender4116]

This video is not in your CCNA Playlist and should be added. Awesome video though.

[@thethirdtomas3]

What’s a “rooter” though?

[@aartikarande227]

) allow the students

[@mumblic]

Sadly another video without a real explanation how it works

[@JuiceManTech]

Does the not going over 15 correlate to the RIP routing protocol or am I way off here? Thank you for your awesome videos.

[@MrReklez]

Not related. NTP stratum only increases when additional reference clocks are added in the heirarchy

[@vladislavkaras491]

Great explaining video! Thanks!

[@serikkuzhambayev6275]

Cool +6

[@TechRL4952]

Thanks for the video CertBros,

[@Certbros]

You're welcome Pablo! Thanks for the comment. 👌

[@Anton604-e4j]

Can you make a video about RSTP plz

[@keithfox1323]

Gotta get that first comment going

[@Certbros]

You got it! 👍👌

[@piotrkondzioka4009]

great video! thanks

[@Certbros]

Thank you!

[@vipin9634]

Is syncing your master device to NTP server through internet is a one time process or we need a life long internet connection as and when we need to operate our devices.

[@vipin9634]

Here I have a master device which I have synced to NTP server via internet and In turn I am syncing my slave devices over internal network. Do I need a life long continues internet connection for syncing my master device to ntp server or it's just a one time process?

[@BR-hp3tm]

how come router 2 has two stratum value 4 and 3..would appreciate the explanation please ?

[@Certbros]

Sorry for the late response Bodhi. Router 2 has a stratum value of 4. R1 (one hop closer) has a stratum value of 3. You can see R1s stratum value in the show ntp associations command. Hope this helps.

[@michaelcasana8376]

bro these videos are so legit thank you

[@sgshobigamer890]

Good 👍

[@dyvakumarchikkala3308]

its really a good explanation

[@nicole.9889]

Thank you for this video! Taking Net+ soon

[@Certbros]

Good luck! You’re going to smash it.

[@barbobrien9318]

Well done.

[@Certbros]

Thank you!

[@agstechnicalsupport]

Well explained, thank you !

[@rneelakantan1214]

Crisp and clear, well explained..

[@toniabed9561]

Great explanation

[@popukuttansvlog1106]

♥️

[@franciscoborges9426]

Thanks for the upload, clear, concise and to the point.

[@Certbros]

You're welcome! Glad you liked it!

[@alperen843]

Great video, thank you but I wonder how we can reduce the delay. Can you give an idea?

[@emmanueladuku8136]

Great piece of work man....you are doing so well in breaking topics down to toddlers' level.

[@Certbros]

Thank you Emmanuel! Great to hear you liked it!

[@jani140]

Isn't this a re-upload? Such an old topic...

[@Certbros]

Not a re-upload. Just trying to cover the topics on the CCNA 200-301.