Cisco ntp sync Information About Network Time Protocol How to Configure Network Time Protocol Configuration Examples for Network Jan 7, 2017 · While I was doing a lab about time-range based access-list, I have some problem trying to synchronize the router that acts as ntp server and the router client. Dec 9, 2020 · So I’ve googled this and read a lot - more than I ever wanted to know about ntp I think. 1 If I want to sync all the phones to a NTP source, is there more to it than pointing to a server in the "Phone NTP Reference" and then add the NTP reference in "Date/Time Group"? I've reset:ed the phones. Nov 2, 2015 · I have two border routers that get time from external NTP servers while delivering it to my internal network devices. “show running-config ntp” 必要な設定 Aug 14, 2025 · NTP CommandsUsage Guidelines For usage guidelines, see the Cisco IOS XE, ntp authentication-key command. Is there something more besides setup "ntp server" and timezone ? synchronised to local net at st Oct 27, 2017 · Hello All, can anyone tell me why we are not able to sync NTP from Nexus 9504, 93180, 92160, two command we configured: #ntp server 10. every day is got the following error: Cause: No NTP Server reachable from SPCISE01 Details: All of the NTP Servers configured on this node are unreachable. Also, have you checked that the NTP server has a route back to your router that is not syncing, and vice-versa? Dec 8, 2023 · Hi, Switch - CISCO Catalyst 2960-48TT - NTP time sync issue. These services allow the products to accurately keep track of the current time and date, to synchronize multiple devices to the same time, and to provide time services to other systems. Unfortunately ISE always select LOCAL(*127. It can be elected as the next in-sync peer if the current one is deleted. (See MS KB 875424 for more info). 3 (3)F, in line with the RFC 8573 standards, NTP security is enhanced with the AES128CMAC authentication mechanism along with Type-6 encryption support for authentication keys. This section contains payload examples and CLIs to demonstrate how to use the NX-API REST API to configure NTP on Cisco Nexus 3000 and 9000 Series I would like to synchronize a Cisco Catalyst 2960 series switch with a publicly available NTP server such as time. This chapter describes the Cisco IOS XR Network Time Protocol (NTP) commands used to perform basic network time management tasks, including synchronizing time settings and coordinating time distribution over the network. Jan 19, 2021 · Network Time Protocol (NTP) is a protocol designed to time-synchronize a network of machines. Ntp can take a long time to sync when the server is reporting significantly different times. This router is also the GW for ISE. From Cisco IOS Basic System Management Command Reference - N through T Commands [Support] - Cisco "If you are using NTPv4, the NTP synchronization takes more time to complete when compared to NTPv3, which synchronizes in seconds or within of 1 to 2 minutes. It is currently synched to an outside NTP server. has anyone ever experienced this? thanks Apr 23, 2024 · Background Information You can use Network Timing Protocol (NTP) to synchronize time and clocks across network connections. 4E which cannot sync to ntp server. What could be the issue? Feb 4, 2010 · Does anyone know how often NTP updates on Cat switches? I believe you can set it on routers but can you set the frequency on switches? Sep 13, 2024 · NTP Overall Time-Sync Status: Ntp Config Failed please help me removing my current NTP server and re add it on my FPR1120 running on FTD code using CLI, as I dont have GUI access. 3se), but I have a 3850 with version 3. I have tried to point my cisco device to my domain controller as the NTP server but without success. Oct 10, 2018 · Dear Team, I am facing NTP Synchronization issue. 34. NTP does not sync up properly if it is off by more than a certain amount of time. Then point all other devices to the NTP Masters to sync. 532 est Sat Jan 28 2023 ntp server#sh clock 20:49:33. May 13, 2024 · Hello @Xiao Guai Yes sir! ntp master x command under configuration terminal. Use Cisco Feature Navigator Check what IOS you are using: Look for potential bug Check version Network Time Protocol (NTP) is a protocol designed to time-synchronize a network of machines. 110 ( change the IP address) # show clock # show run | in ntp as per the output it polled as client mode = - polled in client mode The mode in which a host polls a time server that it might synchronize with, but it will not respond to polls from that time server. Feb 18, 2024 · NTP is used to allow network devices to synchronize their clocks with a central source clock. 117 R1#sh ntp assoc address ref clock st when poll reach delay offset disp *~139. When an NTP server or client is configured, NTP features are available on all router interfaces. NX-OS の NTP コマンドについて 3. The routers do have access to the NTP s Jun 10, 2009 · Before setting up routers to sync with time sources Check what kind of router/software version you are using: Certain lower end platform supports only SNTP. The best way to ensure proper time synchronization between Firewall Management Center and all managed devices is to use an NTP server on your network. CLI commands: Show ntp associations show ntp status show run | inc ntp Do I have ntp wo Jul 18, 2012 · This document provides a sample configuration of how to synchronize the clock of the Cisco Adaptive Security Appliance (ASA) in multiple context mode with that of a Network Time Protocol (NTP) server. In a network, if all the devices are not connected to internet directly, we can configure a Router (which is connected to internet) to synchronize its time from Public NTP Time Servers and remaining devices to syncronize from the first Router. Synchronization is the process of coordinating or aligning two or more events, signals, systems, or processes to work together in time, frequency, or phase. If NTP is unable to synchronise on a Cisco switch or router you may resolve the root cause and the device will still not be synchronised when we check. sync any of the cisco router/switch with internal NTP and i make this ntp synced router/switch as a NTP server for CUCM. There is a considerable amount of information in the output, which includes packet loss information. Sep 30, 2016 · Hi all I had a FMC and 2 Firepower all running version 6. Mar 14, 2024 · The NTP algorithms are engineered to resist attacks when some fraction of the configured synchronization sources accidentally or purposely provide incorrect time. Check version specific release notes. Aug 1, 2019 · This chapter explains how to configure timing ports on the Cisco ASR 920 Series Router. i want to sync the clock of firewall from on ntp server on internet, or with internal domain controller that is inside LAN. x prefer #ntp source-interface Vlan (mgmt) We are able to sync from WAN router but not any of the Nexus switches. NTP Services on a Specific Interface Network Time Protocol (NTP) is a protocol designed to time-synchronize a network of machines. Nov 4, 2013 · I have been having issues with a 3750X Stack that is not synchronizing with our NTP server. But there is a little homework you should to do make sure you implement a NTP configuration that will perform well. Just to double check. NTP services are disabled on all interfaces by default. NTP then distributes this time across the network. I had no problem to sync ntp server with most of 3850 switches (e. I have synced the FMC by using ntpdate -u 192. It ensures consistency, precision, and smooth interaction Dec 1, 2023 · This document describes how to troubleshoot Network Time Protocol (NTP) issues on Cisco DNA Center (DNAC). If NTP authentication is configured ensure that key ID Sep 27, 2022 · Hi I have configured NTP server on a core router (4431) to synch time with ISE. Ensure that C9300 is able to sync its own clock with a reference source, as explain @Leo Laohoo Jun 22, 2009 · Introduction How to configure NTP and SNTP on the Cisco AP Resolution A NTP network usually gets its time from an authoritative time source, such as a radio clock or an atomic clock attached to a time server. Cisco ISE implemented on distributed mode, where there are two Cisco ISE inst In Cisco devices, NTP Configuration is done with these NTP commands. An NTP network usually gets its time from an authoritative time source such as a radio clock or an atomic clock attached to a time server. (No need to check time to time) So once our device is synced with NTP server, then we check the difference of hours between the synced time and the local time in our device. 16. g. Sometimes some or even all of the configured exrernal servers go down, so we lose the sync. I am able to ping the ntp server in my WLC. NTP Services on a Specific Interface Jan 12, 2024 · A stratum 2 NTP server receives its time through NTP from a stratum 1 time server. (or if you use a unix or windows ntp server, check the configuration, if the ip addresses of your nexus9k are allowed to use the ntp service). SEAA(conf)#ntp server 128. Apr 15, 2025 · The clock manager is the component in the Cisco NTP to PTP software architecture that keeps track of the various time services and selects the clock that actively provides time. I have manually setup the time with the correct timezone and offset. The server then provides clock information to its NTP clients (strata 2 and 3). The feature is supported on Cisco Catalyst IE9300 Rugged Series Switches beginning with the Cisco IOS XE Cupertino 17. To remove configured peers and servers, use the no form of this command. May 2, 2024 · I have a fire power 2100. 9123. By default, NTP services are disabled on all interfaces. Feb 9, 2025 · Troubleshooting PTP as an NTP Reference Clock PTP as a Reference Clock for NTP You can configure Precision Timing Protocol (PTP) time as the reference clock for Network Time Protocol (NTP) by enabling the feature on the IR8340 router. Dec 16, 2024 · Network Time Protocol (NTP) is a protocol designed to time-synchronize devices within a network. I have tried adding and removing the NTP server but it does not help. configured NTP on cisco I have… Apr 17, 2019 · The objective of this document is to provide and explain the (CLI) steps to enable an SNTP server to synchronize time settings for a switch. NTP Services on a Specific Interface Aug 11, 2023 · Hi, I have setup 2 C9800 in a lab environment and cannot get the clock to sync. Cisco IOS XR software implements NTPv4. The current NTP server is running a local clock and according to theory it should serve its own time to NTP clients right? I know Jun 8, 2021 · Hello Community, How to set up ntp time synchronization with a specific server (time pattern in my LAN) on a Catalyst C1000 switch (web gui or cli) ? Regards. 9. x, 3. 03. Any suggestions would be great! Thanks! Feb 15, 2011 · Hello everyone, I'm need synchronization clock device ( Switches e routers ) of the my network with a server ntp inside network. I am trying to write a script that checks the NTP status and notifies me if NTP is either 1. Information About Implementing NTP Configuring NTP Information About Implementing The only way to sync the time on routers and switches is to use NTP server. Jul 11, 2023 · This document describes how to validate NTP configuration, change & troubleshoot the NTP service. 31 the switch clock keep show the same hour and date. My current configuration is having host 172. Step 2 Configure Windows to use Cisco NTP Time In the past I’ve said “Windows Does not use NTP, it uses Win32 Time” This is not strictly true, it does use NTP, but by default it uses ‘Symmetric Active Mode NTP’ and your Cisco Device expects its NTP requests to be submitted via ‘Client Mode NTP ‘. 127. Jul 16, 2008 · I am having issues with 3600 and 7200 routers not sysncing with NTP server. This document describes a problem that is encountered when the Cisco Identity Services Engine (ISE) and other Linux-based servers fail to synchronize with a Network Time Protocol (NTP) server that is installed on a Microsoft Windows Server. Dec 27, 2022 · Cisco Community Technology and Support Networking Routing %IP-IP_NTP-5-SYNC_LOSS : : Synchronization lost 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 time synchronization Configure NTP Additional references for NTP Release information for NTP NTP time synchronization When multiple time sources are Nov 6, 2025 · This tutorial explains how to configure NTP Server and NTP Client in Cisco Router step by step with practical example. 133 EST Sat Jan 28 2023 Config at NTP client: 1 56 WS-C3850-48P 03. ntp {peer hostname | server hostname} [prefer] [use-vrf vrf-name] no ntp {peer hostname | server hostname} Syntax Description Mar 24, 2021 · Use ntp server time. The Problem is time is no If you use "ntp access-group" commands, check the referenced access-lists. Sep 12, 2024 · Network Time Protocol (NTP) is a protocol designed to time-synchronize a network of machines. So the basic answer to your question is that no Cisco NTP is not compatible with Microsoft NTP. Network Time Protocol (NTP) is a protocol designed to time-synchronize a network of machines. 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. Issue: ntp client#sh clock 21:05:46. The Firewall Management Center supports NTPv4. Clocking and Timing Restrictions Clocking and Timing Overview Configuring Clocking and Timing Verifying the Configuration Troubleshooting Configuration Examples Clocking and Timing Restrictions The following clocking and timing restrictions apply to the Cisco ASR 920 Series Router: Do not configure GNSS in Jan 7, 2002 · You may need to set the system time on the router manually then apply NTP. Dec 7, 2010 · Hello I've tried many different combinations and have not been able to get NTP to synch. NTP topic will be covered for CCNA, ENCOR, ENARSI and SCOR exams. Below lab topology, the Cisco Router "OmniSecuR1" is connected to internet directly and synchronize its time from public NTP time servers. The issue I am facing is that time on ISE is not syncing with NTP server. x. Information About Implementing NTP Configuring NTP Information About Implementing Jan 17, 2024 · Looking for some assistancerunning into some odd behavior with authenticated NTP NTP synchronization always fails when authenticated Source: Cisco 4451 and 4331 routers are NTP sources (Running IOS XE 17. Information About Implementing NTP Configuring NTP Information About Implementing Nov 11, 2025 · If you are using NTP, you can view the overall synchronization status on the Current Time tab, or you can view the synchronization status for each configured NTP server by looking at the Server Status field in the NTP Server table on the Time Synchronization tab. Aug 5, 2014 · Hi folks, Wondering if anybody knows the reason why a Cisco ISE is not in sync with NTP server. ACS 5. x is allowed to configure up to two NTP servers. Its applicable for Cyber Vision Center 2. Probably one of the most common issues in failure of NTP is a problem with IP connectivity. Mar 22, 2024 · My experience has been you only need to set ntp master if you are trying to make it be an ntp server while using the internal clock. The acceptable time for synchronization in NTPv4 is 15 to 20 minutes. ntp master [stratum level] Jul 26, 2011 · All Cisco devices provide an array of time-of-day services. 6 code)…pulling from public NTP (sync'd stratum 2 & 3) Clients: Several Cisco 3850 switches ( Sep 30, 2012 · I am currently implementing Cisco ISE in our client. Apr 14, 2025 · This document describes a simple configuration and validation for a Nexus 9000 platform to act as both Network Time Protocol (NTP) server and client. In this example, we will see how to configure NTP on Cisco devices. com. NTP Jan 23, 2023 · I am having issues with Cisco 9500 switches and WS 2016 with configured NTP , can sync to public NTP servers on the internet but cannot sync to my internal NTP server. You can manage the system time and date settings on your switch using automatic configuration, such as the SNTP, or manual configuration methods. You can try manually setting the clock then wait for the synchronization. Aug 19, 2020 · Hello, Cisco C9800-L WLC is not being synchronized with NTP server. 2 Sep 5, 2024 · Implementing Network Time Protocol (NTP) The current NTP version is NTPv3 which supports only ipv4, however, there is an extended version available NTPv4, supports both ipv4 and ipv6. nt Hi Ping, "Insane", I like that one. However, i got this "unsynchronized" word on the show ntp status result. Currently Cisco ISE just synchronize to local. Sep 16, 2025 · About Timing and Synchronization Documentation Features Introduced in Cisco IOS XR Products and Releases What is Timing and Synchronization? Frequency Synchronization Precision Time Protocol (PTP) Network Time Protocol (NTP) Global Navigation Satellite System (GNSS) Network Synchronization Design Best Practices Sep 12, 2024 · Support for Synchronization of Time and Frequency: Unlike NTP, which only synchronizes time, PTP can also synchronize frequency, which is important in some applications. I checked the hardware Jan 31, 2013 · This chapter describes the system management commands that begin with N. The FTD looks like its the problem since it says unknown. ntp To configure the Network Time Protocol (NTP) peers and servers for the switch, use the ntp command. SEAA-0 May 19, 2017 · Hi, I am struggling with NTP sync for a lab. sh ntp status Clock is unsynchronized, stratum 16, no reference clock nominal freq is 119. Pls find below command output step by step for easy understanding. google. For network devices like routers, switches, or firewalls this is very important because we want to make sure that logging information and timestamps have the accurate time and date. Jul 7, 2023 · Finally, you can configure Cisco devices to act as a time servers, also known as NTP Masters, on your network. NTP server is Windows Server 2022 (Domain Controller). Note that ISE is VM-based. Cisco Switches are not Synchronized with NTP Server. Use Below command to make the router/switch a NTP server. THank you Dec 1, 2023 · Network Time Protocol (NTP) is a protocol designed to time-synchronize devices within a network. Sep 19, 2009 · Hi, Am trying to sync the time of my cisco devices to the time of my domain. Aug 27, 2018 · we have one switch cisco 3850 configured as a ntp master. 2(25) I am examining a requirement to configure C2960 as below NTP internet sources > C2960 > Domain Controllers > other devices and servers In theory what I am trying to achieve is to synchronize C2960 with multiple NTP internet sources which then would act as server Sep 23, 2025 · The terms IR8340 and router are used throughout this document in text and CLI examples to refer to the Cisco Catalyst IR8340 Rugged Series Router, unless otherwise noted. What NTP server software are you running on your Windows 10 box? Has it been configured correctly? Have you check with Windows firewall is configured to allow traffic to UDP port 123? If you run a packet capture on your Windows 10 device, can you see the NTP traffic being received an responded to? NTP has not succeeded at all as it is not in sync and doesn't This lesson describes the most common NTP (Network Time Protocol) issues and how to troubleshooting should be done on Cisco IOS devices. Nov 7, 2012 · hello guys, I'm having problems with the cisco ise in my company. はじめに このドキュメントでは、Nexus シリーズで実装されている NTP のトラブルシューティングを提供します。 2. Kindly help me understand what would be the possible list of issues. Mar 31, 2025 · After NTP authentication is properly configured, your networking device will synchronize with and provide synchronization only to trusted time sources. The network is isolated from any outside connection. NTP runs on User Datagram Protocol (UDP), which in turn runs on IP. May 14, 2025 · This document describes how to configure, verify and troubleshoot Network Time Protocol (NTP) on Firepower FXOS Appliances. version 3. Aug 24, 2023 · Solved: Hi All, I wanted to configure the NTP server in our network. I noticed that it takes me more than five minutes to achieve a full synchronization between the two routers. Includes troubleshooting commands, examples and parameters. Oct 12, 2023 · PTP time acts as a stratum 0 source, and the Cisco IOS NTP server acts as a stratum 1 device. Define your NTP Strategy Before you start, you need to determine your NTP strategy. Networking devices running NTP can be configured to operate in a variety of association modes when synchronizing time with reference time Jun 26, 2020 · w I want FTD change Timezone to UTC+07:00 Timezone and sync time with NTP server. The following guidelines and limitations are applicable: This feature Timing and Synchronization Configuration Guide, Cisco Catalyst IE9300 Rugged Series Switches First Published: 2023-10-12 Sep 25, 2021 · It just means to sync with the NTP authorative server and whenever there is some changes in time in NTP authorative server it automatically changes in our device. . 0 and if ntp status says unsynchronized then these are signs that your ntp configuration is not working. May 28, 2024 · This document describes how to configure NTP authentication on Cisco Identity Services Engine (ISE) and troubleshoot the NTP authentication issues. Does we have any configuration to force the ISE to sync time with Window Server? Thank for your kindly support. The 3600 and 7200 routers can sync to public NTP servers on the internet but cannot sync to my internal NTP server. To disable the authentication of the identity of the system, use the no form of this command. On both the FMC and FTD i get Time Synchronization Status May 2, 2024 7:33 AM FC is out-of-sync. This synchronization allows you to correlate events when you receive system logs and other time-specific events from multiple network devices. 117 204. Most Cisco devices have two clocks: a battery-powered hardware clock (referenced in CLI commands as the calendar) and a software clock (referenced in May 26, 2012 · hi, i am setting a C1841 to sync its time with another C1841 over net. apple. Nov 12, 2018 · Hi, I have a log fault, which says that my NTP doesn't sync. Nov 5, 2008 · Cisco IOS-NTP, which tries to sync with W32Time, gets its own root-dispersion value that it sends to the W32Time and this proves costly for Cisco IOS-NTP to synchronize. This question is closed since I already have answer from you. 40 2 23 64 377 32. In these cases, a special voting procedure is used to identify spurious sources and discard their data. My NTP server is working fine as I have other devices syncing to it. A Network Advantage license is required. NTP Overview The Network Time Protocol (NTP) synchronizes timekeeping among a set of distributed time servers and clients. Jun 12, 2019 · I configured NTP point to my Window server for time synchronization. I have reviewed the knowledge base article here: Catalyst 2960 Configuration Guide but am not entirely sure which parts of the "Configuring NTP" subsection are relevant to my configuration. On Cisco routers, you can use the show ntp associations command to see the status of NTP peers. Good day everyone. 198. Keep in mind, NTP servers are in AD. Does anyone know how to sync both of them? show ntp NTP Serv Jan 28, 2014 · Solved: Hi there! i've setup a site, with cisco ASA 5505. I also tried to sync to exte Jun 13, 2025 · Network Time Protocol (NTP) is a protocol designed to time-synchronize devices within a network. Certain releases of Cisco IOS support either the Trimble Palisade NTP Synchronization Kit (Cisco 7200 series routers only) or the Telecom Solutions Global Positioning System (GPS) device. 0 54201. 1. Firepower time is using Firesight time,, while Firesight is point ot outside NTP server. SE n If you can give your NTP server device Internet access try configuring it to sync with a legit NTP server on the Interwebs. I am running a windows server 2008 domain but I am not using an external time source. NTPv4 retains backwards compatibility with the older versions of NTP, including NTPv3 and NTPv2 but excluding NTPv1, which has been discontinued due to security vulnerabilities. 0) as a time source. Hi to all, Im configuring NTP on my catalyst 9300 pointing to a server which has the NTP software. I am able to ping servers from ISE and the Wireless Controller is successfully synchronized. I also configured it with "clock time zone +3" to align the time. 3. 2 CLIENT: ntp server 10. here is my setting with dont work ! SERVER: clock set 23:01:00 26 MAY 2012 ntp master 5 ntp source f0/1 ntp access-group serve-only 10 access-list 10 permit 10. 概要 NTP が同期できない場合に実行すべき NTP コマンド、及び主に確認すべき箇所について解説しています。 3. 5 days ago · Complete guide to NTP Server and Client configuration on Cisco router. CSA_SW#show clock detail . No router. org in my lab. Information About Implementing NTP Configuring NTP Information About Implementing Jun 15, 2012 · This document provides a sample configuration for the Cisco ACS to synchronize its clock with NTP server. Learn basic concepts of NTP such as what NTP is, how NTP works, NTP stratum levels, meaning of synchronized and un-synchronized NTP clock in detail. The show clock shows the correct time, however this "unsycronized" messeage really bothers me. 19:28:40. Jan 28, 2023 · Helllo, We do experience the following issue: Clock between Client and Server is off by 16 minutes, though NTP is synchronized. 0. If you have an ntp server that your switch can sync from, you don't need the ntp master statement. NTP is extremely efficient; no more than one packet per minute is necessary to synchronize two machines to within a millisecond of each other. May 1, 2023 · This document describes common issues with time synchronization on FireSIGHT Systems and how to troubleshoot them. 02. But are there any ways to get this to work again without recon Synchronize Time on Classic Devices with an NTP Server Synchronizing the system time on your FMC and all its managed devices is essential to successful operations. We are able to do sync from Cisco 6509 a Sep 19, 2008 · The Cisco NTP client wants to synchronize with a full implementation of NTP on the server and will not synch to W32Time. 100. This module describes how to configure Network Time Protocol on Cisco devices. Can I set up one of the switches as an NTP server and the other will sync with that switch? Thanks, Yared. Jan 3, 2018 · show NTP on NGFW-FTD02 shows that NTP is associated with the local clock. Apr 23, 2025 · Beginning with Cisco NX-OS Release 10. But having a little problem that Cisco ISE can not synchronize with the NTP Server. Verify you don't see any other ntp servers listed. 33. 168. The ultimate goal […] Dec 10, 2018 · After NTP authentication is properly configured, your networking device will synchronize with and provide synchronization only to trusted time sources. Jul 7, 2013 · Hardware - C2960 IOS - 12. Feb 17, 2021 · Can you post below output : # show ntp statistics peer ipaddr x. in ntp master we use just ntp master command and another switch we use ntp master switch loopback ip as a ntp server. Jun 11, 2009 · Platform: CUCMBE 6. Mar 22, 2007 · If the reference clock is 0. com if organization allow external NTP sync. A candidate NTP server means it is a valid one and has successfully communicated with the Firepower appliance, but the module has been synchronized with another NTP server so it is the standby one. 1 release. You must have Admin or Network Admin privileges to do this procedure. PTP time acts as a stratum 0 source, and the Cisco IOS NTP server acts as a stratum 1 device. * - selected for sync Device is synchronized to this source Configuring NTP he Network Time Protocol (NTP) synchronizes the time of day among a set of distributed time servers and clients so that you can correlate time-specific information, such as system logs, received from the devices in your network. I have the below configuration R1: NTP is synced with an authoritative server R1#sh run | s ntp ntp server 139. 66 act as an NTP server with NTP server software. Network Time Protocol (NTP) Commands This chapter describes the Cisco IOS XR Network Time Protocol (NTP) commands used to perform basic network time management tasks, including synchronizing time settings and coordinating time distribution over the network. Information About Implementing NTP Configuring NTP Information About Implementing Jul 19, 2013 · Start a conversation Cisco Community Technology and Support Networking Switching NTP time not synchronize with Logging Bookmark | Subscribe May 31, 2010 · Time sync in ntp client and server generally used to excahage several packet where each exchange is a pair of request and reply. 1X testing. Thanks, Jong Time synchronization among all of the components of your system is critically important. The following example shows how to configure the system to synchronize only to systems providing the authentication key in their NTP packets: Router(config)# ntp authentication-key 65535 md5 test The following example shows how to remove all the configured NTP options and disable the NTP Nov 22, 2023 · This document describes Network Time Protocol (NTP) for Cisco Unified Communications Manager (CUCM). Nov 26, 2019 · After NTP authentication is properly configured, your networking device will synchronize with and provide synchronization only to trusted time sources. Other two Nov 4, 2025 · This document describes how to troubleshoot Network Time Protocol (NTP) issues with debug commands and the show ntp command. The connection to the NTP server was disconnected briefly but after the reconnect NTP hasn't syncroniced. I have attached screenshot of the output of show clock and show NTP commands. I have purchased an used Catalyst 2960s from eBay and everything seemed to be working great after the initial configuration except the time set on the clock doesn't synchronize after reboot. Appreciate if someone can help me to correct this problem. Apr 30, 2024 · Hello everybody so i have been assigned to a task from my manager he wants me to activate ntp on a cisco switch (catalyst 9200 ) i have all the command line but he keeps telling me you are missing something not on the commands but where to apply this ntp on which interface keep in mind we have a Apr 20, 2020 · Configuring a Cisco IOS device (router/switch) is probably one of the easiest things that you can do. NTP Version 3 is documented in RFC 1305. Is it possible to use a windows ser Sep 23, 2025 · Network Time Protocol (NTP) synchronizes time in a network and provides: synchronization of time across a network of machines, and UDP over IP. NTP version 3 is defined in RFC 1305. I've done the command follow in a switch ( for test ) but it isn't working. Apr 7, 2005 · The Cisco Small Business Switches support Simple Network Time Protocol (SNTP), and when enabled, the switch dynamically synchronizes the device time with time from an SNTP server. It would probably start to work if i remove and add the ntp server statement againt. My router and switch then use the 172. The feature is supported on Cisco Catalyst IR8340 Rugged Series Routers beginning with the Cisco IOS-XE Release 17. This is because the device will wait until the next polling interval to try again. I do not remember the exact limit, but I know its more than 5 minutes. You can use one of the network devices, but an AD domain controller would also do the job. The time always dialed back to the year of 2006 after restart, and consequently, the NTP doesn't sync until I manually set the clock again, which is a bit painful. And the ntp server is reachable. It has public ip also. Oct 3, 2023 · In Viptela OS, show ntp associations command displays different codes during the connection process that provides information about the stage the synchronization is on. Beginning with Cisco NX-OS Release 10. 1 source loopback 0 ntp up Jan 3, 2011 · Hello Dear's, Please find the attached I have configured Core Switch as a NTP server on ASA firewall, ASA firewall inside interface is connected to Core switch and the IP Address of NTP server is directly connected subnet between the ASA Inside interface and CORE switch. 66 address for thei Oct 12, 2023 · Precision Time ProtocolMessage-Based Synchronization PTP Event Message Sequences Best Master Clock Algorithm PTP Clocks PTP Profiles PTP Profile Comparison Tagging Behavior of PTP Packets Configurable Boundary Clock Synchronization Algorithm NTP to PTP Time Conversion GMC Block Guidelines and Limitations Default Settings Message-Based Synchronization To ensure clock synchronization, PTP Nov 4, 2025 · 本文說明如何使用debug命令和show ntp命令對網路時間協定(NTP)問題進行故障排除。 ntp trusted-key To authenticate the identity of a system to which Network Time Protocol (NTP) will synchronize, use the ntp trusted-key command in global configuration mode. when we update another switch time form ntp server its update time but, its time is diffrent form our ntp master switch. Nov 6, 2025 · This tutorial explains how to configure NTP Server and NTP Client in Cisco Router step by step with practical example. We have a Cisco ISE 2. I use servers from ntp. Sep 7, 2022 · Cisco Community Technology and Support Data Center and Cloud Application Centric Infrastructure ACI - NTP Server not selected for sync Aug 13, 2025 · This document describes how to configure AireOS Wireless LAN Controllers (WLC) to synchronize date and time with a Network Time Protocol (NTP) server. 268 IST Fri Dec 8 2023 Time source is NTP CSA_SW#show ntp associations address r Nov 8, 2019 · Hi there, I setup NTP server on a domain controller. All the best for your exam preparations. 2(1)E. When sending out a request, the client stores its own time (originate timestamp) into the packet being sent. Sep 19, 2024 · The symmetric active mode is used between NTP devices to synchronize with each other, it’s used as a backup mechanism when they are unable to reach the (external) NTP server. 2088 Hz, precision is 2**18 Candidate: The host is the candidate (standby) peer. 1 (1), Cisco Nexus 9000 switches do not sync with stratum 14 and 15. We are running Version 15. Jan 31, 2012 · Cisco may apply more stringent requirement that it can only synchronize with NTP server or device with NTP daemon. 2. 2092 Hz, actual freq is 119. 7. FMC and one of the Firepower time is correct point to NTP server time, another firepower unit is out of sync, Time different is this Firepower usin Sep 15, 2016 · Hi I have a 3850 switch with NTP configured. To have synchonized times, we use an NTP server in the same subnet as the ISE to sync all the components (stratum 3, based on Bluecat Apr 15, 2025 · PTP time acts as a stratum 0 source, and the Cisco IOS NTP server acts as a stratum 1 device. I have a cisco 2960 swtich, I want to sync the time on it from my windows 2019 domain controllers. x, 4. Jun 3, 2008 · Hi, I need some help, I have configured my ntp server server in my WLC but i jut noticed that the time is not syncronized. 59. 0 in our lab doing some 802. Jul 7, 2014 · This lesson explains how to configure NTP on your Cisco network devices including access-control and authentication. and how do I sync clock from NGFW-FTD02 without being on FMC (need a command), also help me understand the routing issue here as I am unable to reach the gateway (mostly gateway /data interface issue) and Sep 17, 2025 · Network Time Protocol (NTP) is a protocol designed to time-synchronize devices within a network. 10. Upstream is open. I tried to re-enable ntp server on the switch.