Small business routers with dns and ntp windows#

So just as in the above command the syntax is looking for a WORD after ‘summer-time.’ This should be something meaningful to you as an administrator, so the Daylight equivalent abbreviation for your time-zone. The commands will be similar: switch(config)#clock summer-time EDT recurring Next, let’s configure Day Light savings time. Not sure what your offset is? Check here. Then, set your offset in hours from Universal Coordinated Time. For me, I used EST because I am in the Eastern Standard timezone. This word should be something meaningful for you so you know the timezone you’re setting. switch(config)#clock timezone EST -5Ĭlock timezone and then a WORD. I’m very familiar with UTC but when I’m looking through logs and such I prefer to see local time. NTP Client Configīy default the clock on a Cisco device uses Universal Coordinated time as its default time zone. Then point all other devices to the NTP Masters to sync. (Note this all happens by default and does not need to be configured)įinally, you can configure Cisco devices to act as a time servers, also known as NTP Masters, on your network. The Root Forest Domain PDC Emulator then syncs with an external time source, by default it uses the Microsoft hosted time server of.

In larger AD Forests the PDC Emulator in a child domain get’s it’s time from any DC in a parent Domain or the PDC Emulator of the Root Forest Domain. Any Domain Controller in a domain get’s it’s time using NTP from the PDC Emulator.

Small business routers with dns and ntp windows#

In a Windows based network you can use any Domain Controller. You can use to sync to your nearest NIST time server.Īnother popular time source is, which is the home for the Network Time Foundation, creators of NTP.Īnd of course, Google is in on the action too! You can also use and get your time from the atomic clocks located in Google’s data centers around the world! NIST is the National Institute of Standards and Technology and manages several Atomic clocks in the United States, and collaborates with other standards organizations around the world. So, what are your time source options? Simple, you can go direct to the source and connect to a NIST time server.

The stratum is important because using the stratum NTP can make corrections and align itself more closely with an atomic clock, so that regardless of the stratum level your device is getting it’s time from all devices will be within milliseconds of one another, and that’s some pretty accurate time! Time Source Options A device getting its time from a Stratum 1 server is a Stratum 2, or 1 hop away. A device getting it’s time directly from an NTP server is said to be stratum 1. NTP uses stratums to define how far away from an atomic clock a NTP server is. In short they super cool atoms to slow them down and then measure the atoms vibrations using lasers. Sources of TimeĪround the world there are many atomic clocks that keep very accurate track of the time. Time zones are configured locally on the client device, generally speaking, and then the client device does the math to display the human friendly version of the time. There is no data around timezones or anything like that shared in NTP timestamps. The time stamps are basically counting the number of seconds from a known point in time. NTPv4 is defined in RFC 5905, and NTPv3 is defined in RFC 1305.Īs stated previously, NTP utilizes UDP to share time stamps. However, v3 and v4 are both widely accepted, with v4 being backward compatible with v3. Currently, there are four versions of NTP, with v4 being the most recent. NTP stands for Network Time Protocol and uses UDP port 123. Devices stay in sync by using NTP to periodically poll a time source for the time. Additionally, many other networking services rely on network devices to be in sync. So, the solution is to use NTP, or Network Time Protocol, and synch all of your network devices to a common time source. If the time is off from device to device it will make t-shooting events and event correlation that much more difficult.

Why, you might be asking? One example is that SYSLOG log entries are all stamped with the time. Configuring NTP on a Cisco device is an easy, and essential, step when configuring a new router or switch.