NTP And Time Stamps

Categories Cisco

NTP

The Network Time Protocol (NTP) synchronizes the time of day among a set of distributed time servers and clients so that you can correlate events when you receive system logs and other time-specific events from multiple network devices. NTP uses the User Datagram Protocol (UDP) as its transport protocol. All NTP communications use Coordinated Universal Time (UTC).

An NTP server usually receives its time from an authoritative time source, such as a radio clock or an atomic clock attached to a time server, and then distributes this time across the network. NTP is extremely efficient; no more than one packet per minute is necessary to synchronize two machines to within a millisecond of each other.

NTP uses a stratum to describe the distance between a network device and an authoritative time source:

  • A stratum 1 time server is directly attached to an authoritative time source (such as a radio or atomic clock or a GPS time source).
  • A stratum 2 NTP server receives its time through NTP from a stratum 1 time server.

Before synchronizing, NTP compares the time reported by several network devices and does not synchronize with one that is significantly different, even if it is a stratum 1. Because Cisco NX-OS cannot connect to a radio or atomic clock and act as a stratum 1 server, we recommend that you use the public NTP servers available on the Internet. If the network is isolated from the Internet, Cisco NX-OS allows you to configure the time as though it were synchronized through NTP, even though it was not.

Note You can create NTP peer relationships to designate the time-serving hosts that you want your network device to consider synchronizing with and to keep accurate time if a server failure occurs.

The time kept on a device is a critical resource, so we strongly recommend that you use the security features of NTP to avoid the accidental or malicious setting of incorrect time. Two mechanisms are available: an access list-based restriction scheme and an encrypted authentication mechanism.

Config Stuff:
service timestamps debug datetime msec
service timestamps debug datetime msec
service timestamps log datetime msec
service timestamps log datetime msec
clock timezone CST -6 0
clock summer-time CDT recurring
ntp logging
ntp update-calendar
ntp server 128.138.140.44 prefer

12 Comments

  • gate.io
    02/07/2023

    Your article helped me a lot, thanks for the information. I also like your blog theme, can you tell me how you did it?

  • Skapa personligt konto
    04/14/2023

    I don’t think the title of your article matches the content lol. Just kidding, mainly because I had some doubts after reading the article.

  • gate.io para yatırma
    05/21/2023

    I am a website designer. Recently, I am designing a website template about gate.io. The boss’s requirements are very strange, which makes me very difficult. I have consulted many websites, and later I discovered your blog, which is the style I hope to need. thank you very much. Would you allow me to use your blog style as a reference? thank you!

  • Meilleur code de parrainage Binance
    06/22/2023

    Your article helped me a lot, is there any more related content? Thanks! [Link deleted]

  • 20bet
    09/10/2023

    Your article gave me a lot of inspiration, I hope you can explain your point of view in more detail, because I have some doubts, thank you.

  • Darmowe konto na Binance
    12/24/2023

    Your article helped me a lot, is there any more related content? Thanks! [Link deleted]

  • Binance Signup Bonus
    01/15/2024

    Your point of view caught my eye and was very interesting. Thanks. I have a question for you. [Link deleted]

  • conta binance
    02/07/2024

    Thank you for your sharing. I am worried that I lack creative ideas. It is your article that makes me full of hope. Thank you. But, I have a question, can you help me? [Link deleted]

  • bono de registro en Binance
    02/11/2024

    I don’t think the title of your article matches the content lol. Just kidding, mainly because I had some doubts after reading the article. [Link deleted]

  • 註冊binance
    02/20/2024

    Can you be more specific about the content of your article? After reading it, I still have some doubts. Hope you can help me. [Link deleted]

  • dobry sklep
    03/19/2024

    Wow, superb blog format! How long have you ever been running a blog for?
    you made blogging glance easy. The whole glance of your site is great, let alone the content material!
    You can see similar here <a href="[Link deleted]

  • Vytvorenie úctu na binance
    03/25/2024

    Your point of view caught my eye and was very interesting. Thanks. I have a question for you.

Leave a Reply

Your email address will not be published.