Cisco 3750X as a NTP master

Hi All,
I would like to configure my core switches as the ntp master for the environment but also I would like to have the core switch sync with a public NTP server. Can you advise if this is possible? I have seen both commands available on the switch.
Thanks

It is possible but you do not have to use the command "ntp master" on your switch.  Point all your device to the switch and it should work.  
The switch should be able to synchronize NTP with a trusted source.

Similar Messages

  • Using a Cisco Switch as the NTP Master time source for a Windows PDC

    Hi all,
    We have a closed network (no connectivity to the internet) and we have a Core router setup as the NTP Master for the rest of the network.
    All network devices are getting the time synced as intended but we are having issues getting the Primary Domain Controller (PDC) registering to it as a valid NTP time source.
    The problem we have is that we are affected by IOS bug CSCed13703 which rejects the PDC as an NTP associated device. Short of changing the IOS on the Router which is the main router feeding 30 other sites I would like to point the PDC at a different switch (an NTP Client switch) as it’s NTP source, rather than it going to the actual NTP Master.
    I have changed the values in the PDC to point to a different switch (3750) that has it’s time synced with the NTP master, but the PDC doesn’t want to know. I assume it will only accept the time from an official NTP Master .
    Could any of you fine people advise if what I am trying to do is possible and if so how I would go about it. I was thinking of setting the 3750 with the NTP Master command also, but I don’t want to confuse the other cisco devices in the network
    Thanks in advance
    David

    Thanks Marvin,
    I can confirm the Stratum on the 3750 is set to 15.  This is due to the NTP Time source being an internal router and not an authoritative time source out on the internet.  When setting the clock and using the NTP Master command on my internal router it sets the Stratum level to 14.
    I have pointed the PDC at the Router (Stratum 14) and it does successfully sync time, but won't trust it as a valid source after the first sync.  Upon reading I believed this to be the IOS bug as the symptoms are identical. Your theory of the PDC requiring a Stratum 2 time source is logical (especially in this scenario) but I have seen them use Stratum 4 before and it worked just fine.
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    I was going to make the 3750 switch an NTP Master for the Network and point the PDC to it (as per my previous post) but I have noticed this morning that the NTP Master command isn't available on the 3750 as it has no hardware clock!
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    David

  • Cisco Catalyst 3850 as ntp master

    Hi All,
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    2. I have also read that switches also have slow CPU processors that may lack the processing required.
    3. Its NTP sychronization will use external NTP servers which are resolved into IP addresses (e.g. pool.ntp.org). IP address can change. What other more reliable NTP sources are there?
    4. Any other thoughts and comments are most welcome.

    Firstly, DO NOT use the command "ntp master".  Cisco do not recommend using this commands because this will confuse the NTP propagation inside the network.  
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  • C3750X with IOS 15.0(2)SE6 as a NTP master

    Hi All,
    Is it possible to configure a C3750X with IOS 15.0(2)SE6 as a NTP master?
    The configuration guide for IOS 12.2(55)SE states that it cannot function as an NTP master, but the configuration guide for IOS 15.0(2)SE does not state a NTP master.
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    http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750x_3560x/software/release/12-2_55_se/configuration/guide/3750xscg/swadmin.html#pgfId-1053923
    - for IOS 15.0(2)SE
    http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750x_3560x/software/release/15-0_2_se/configuration/guide/3750x_cg/swadmin.html
    Thank you,

    I want the 3750X with IOS 15.0(2)SE6 as a NTP server from other devices in the same network if possible.
    The appliance can perform be as a "server" to other devices downstream PROVIDED the appliance gets synchronized to an authoritative server.  
    This is what we've done to our PCs, printers, phones, etc.  Our core router synchronizes with an authoritative server out the internet.  Our core switches synch with our core router.  Our distro router/switches synch with our core switch.  Our access switches synch with our distro.  PCs, printers, phones, etc synch with our on-site access switches.  

  • Cisco Nexus 7K as NTP server

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    Don't forget to rate all helpful posts.
    http://www.team-cymru.org/ReadingRoom/Templates/secure-ntp-template.html

  • DAC Cable to Cisco 3750x

    Good morning folks, I need to connect my Cisco 3750x with a 10Gb DAC cable to our HP Bladecenter server chassis. What module do I need to purchase for the 3750 in order to do this? Please advise.
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  • Connect cisco 3750X and Dell N4032F

    Hi,
    I need to connect 2 diferent networks (192.168.x.x vs 10.44.x.x). this connection will be temporal because network 192.168.x.x will be migrated to 10.44.x.x.
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    Thanks

    Hi,
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  • CISCO 3750X stacking for 5 switches , only 4 switches are coming in stack

    Dear All,
    I have 5 cisco 3750X switches ,but only 4 switches coming up 5 switches i am unable to see .
    Connection for the switch :Please find the attached snapshot for the stack data connection .
    Also find the snapshot for the stack power connection .
    Please provide your assistance and support to overcome this issue .

    Dear Marvin,
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          format -- Format a filesystem
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       mgmt_show -- show management port statistics
           mkdir -- Create dir(s)
            more -- Concatenate (display) file(s)
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          rename -- Rename a file
           reset -- Reset the system
           rmdir -- Delete empty dir(s)
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          set_bs -- Set attributes on a boot sector filesystem
       set_param -- Set system parameters in flash
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            type -- Concatenate (type) file(s)
           unset -- Unset one or more environment variables
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    Compiled Tue 26-Apr-11 06:59 by abhakat
    switch: boot
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    Error loading "flash:/c3750e-universalk9-mz.122-58.SE2/c3750e-universalk9-mz.122-58.SE2.bin"
    Interrupt within 5 seconds to abort boot process.
    Boot process failed...
    switch:
    All other 4 switches i can see in stack but not these switches and also the status light for this switches is blinking green  please provide your assistance .

  • Cisco 3750x switch. Turning off a port at night

    Hi everyone,
    I have a question regarding power management for the Cisco 3750x Switches. Is it possible to power down switch ports
    automatically at a specific time and if so how. I would like several Ports to be powered down between 2 and 3 o clock at night.
    Can anyone tell me how i can realise this? (these switches have Energie Wise capabilities)
    I hope to hear from you soon.
    Thanks in advance!
    Kind regards,
    Wouter Platteeuw

    few things to try:
    Go to your email setup, go to the account in question, go to filters, Check the box that says "do not forward messages to the device" Set this back to the default if this doesn't work.
    Something else:  try using the blackberry firewall
    http://btsc.webapps.blackberry.com/btsc/search.do?cmd=displayKC&docType=kc&externalId=KB23877
    I think this will block all email though, but you can take a look at the options.
    Please click the Thumbs Up icon if this comment has helped you!
    If your issue is resolved, please click the solution button on the resolution!
    Every BlackBerry should have BlackBerry Protect, get it now! | Follow me on Twitter | Bring Back BBM Music!

  • Unable to hard code the ports of cisco 3750x series switch

    hello,
    I have tried with hardcode to 1000 7 Full on the ports which are connected to another switch.
    After changing the port to auto from one side of the switch port came up. Is there any solution to make port up when both sides are hard coded to 1000 & full duplex.
    Simple Words:
    Switch 1 --> Switch 2 --> Hard coded to 1000 & Full --> Down.
    Switch 1 --> Switch 2 --> Auto on one end to Switch 1  --> Up.
    Switch model:
    Switch 1 Cisco 3750x (Gi Switch)
    Switch 2 Cisco 3750 (Gi Switch)
    Regards,
    Ezra.

    Disclaimer
    The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.
    Liability Disclaimer
    In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.
    Posting
    Yes, it's possible without a straight through cable, enable auto/auto both sides.    Otherwise you'll need a cross-over cable.
    BTW, if your standard is hard coding copper gig ports, for speed and duplex, you might consider bringing your standard up to date.  Copper gig standard went much further in how auto/auto is supposed to work.  By disabling auto/auto, I believe, you're also disabling some error monitoring too.  Generally, all the major players, e.g. Cisco, would recommend auto/auto for copper gig Ethernet.

  • Verify NTP master config

    I have a router BRI_2811_1 which is getting NTP from 10.66.41.201 and this is working.
    When i then wish to make BRI_2811_1 the master for my local network, the internal clock on this router is coming up as "insane". Why is this is so? Eventually i would like all my switches to look to BRI_2811 as their NTP master.
    BRI_2811_1#show run | i ntp|clock
    clock timezone AEST 10 0
    clock calendar-valid
    ntp source Loopback0
    ntp master 6
    ntp server 10.66.41.201
    BRI_2811_1#
    BRI_2811_1#
    BRI_2811_1#show ntp stat
    BRI_2811_1#show ntp status 
    Clock is synchronized, stratum 5, reference is 10.66.41.201  
    nominal freq is 250.0000 Hz, actual freq is 249.9950 Hz, precision is 2**24
    reference time is D8E4D87D.4E30DD39 (00:58:05.305 AEST Sat Apr 25 2015)
    clock offset is -5.1655 msec, root delay is 57.61 msec
    root dispersion is 326.92 msec, peer dispersion is 3.74 msec
    loopfilter state is 'CTRL' (Normal Controlled Loop), drift is 0.000019698 s/s
    system poll interval is 64, last update was 172 sec ago.
    BRI_2811_1# 
    BRI_2811_1#show ntp ass
      address         ref clock       st   when   poll reach  delay  offset   disp
     ~127.127.1.1     .LOCL.           5     13     16   377  0.000   0.000  0.243
    *~10.66.41.201    10.66.9.16       4     48     64   377 22.535  -5.165  3.749
     * sys.peer, # selected, + candidate, - outlyer, x falseticker, ~ configured
    BRI_2811_1#
    BRI_2811_1#show ntp ass det
    127.127.1.1 configured, insane, invalid, stratum 5
    ref ID .LOCL., time D8E4D932.4915B594 (01:01:06.285 AEST Sat Apr 25 2015)
    our mode active, peer mode passive, our poll intvl 16, peer poll intvl 16
    root delay 0.00 msec, root disp 0.00, reach 377, sync dist 2.74
    delay 0.00 msec, offset 0.0000 msec, dispersion 0.24
    precision 2**24, version 4
    org time D8E4D932.4915B594 (01:01:06.285 AEST Sat Apr 25 2015)
    rec time D8E4D932.491675DE (01:01:06.285 AEST Sat Apr 25 2015)
    xmt time D8E4D932.49152E3B (01:01:06.285 AEST Sat Apr 25 2015)
    filtdelay =     0.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00
    filtoffset =    0.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00
    filterror =     0.00    0.25    0.51    0.75    1.02    1.26    1.51    1.75
    minpoll = 4, maxpoll = 4
    10.66.41.201 configured, our_master, sane, valid, stratum 4
    ref ID 43.66.9.16    , time D8E4D803.F3B64840 (00:56:03.952 AEST Sat Apr 25 2015)
    our mode client, peer mode server, our poll intvl 64, peer poll intvl 64
    root delay 35.07 msec, root disp 317.04, reach 377, sync dist 386.52
    delay 22.53 msec, offset -5.1655 msec, dispersion 3.74
    precision 2**10, version 4
    org time D8E4D8FE.4A7EFAA8 (01:00:14.291 AEST Sat Apr 25 2015)
    rec time D8E4D8FE.4EB368F5 (01:00:14.307 AEST Sat Apr 25 2015)
    xmt time D8E4D8FE.48E78643 (01:00:14.284 AEST Sat Apr 25 2015)
    filtdelay =    22.64   22.77   22.53   22.65   22.82   22.97   22.57   22.82
    filtoffset =   -5.10   -5.22   -5.16   -6.06   -5.33   -6.43   -6.73   -6.89
    filterror =     0.97    1.96    2.91    3.85    4.83    5.80    6.75    7.72
    minpoll = 6, maxpoll = 10

    no access groups at all and router is next hop
    HQ-3845#show clock det
    10:40:01.020 AEST Sun Apr 26 2015
    Time source is NTP
    HQ-3845#sho ntp ass det
    127.127.1.1 configured, insane, invalid, stratum 6
    ref ID .LOCL., time D8E6B25A.72DE3D46 (10:39:54.448 AEST Sun Apr 26 2015)
    our mode active, peer mode passive, our poll intvl 16, peer poll intvl 16
    root delay 0.00 msec, root disp 0.00, reach 377, sync dist 2.96
    delay 0.00 msec, offset 0.0000 msec, dispersion 0.24
    precision 2**24, version 4
    org time D8E6B25A.72DE3D46 (10:39:54.448 AEST Sun Apr 26 2015)
    rec time D8E6B25A.72DE9CB0 (10:39:54.448 AEST Sun Apr 26 2015)
    xmt time D8E6B25A.72DE0842 (10:39:54.448 AEST Sun Apr 26 2015)
    filtdelay =     0.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00
    filtoffset =    0.00    0.00    0.00    0.00    0.00    0.00    0.00    0.00
    filterror =     0.00    0.25    0.49    0.73    0.99    1.26    1.53    1.78
    minpoll = 4, maxpoll = 4
    10.66.202.252 configured, our_master, sane, valid, stratum 4
    ref ID 10.66.9.16    , time D8E6B1CB.E328A743 (10:37:31.887 AEST Sun Apr 26 2015)
    our mode client, peer mode server, our poll intvl 64, peer poll intvl 64
    root delay 74.53 msec, root disp 189.16, reach 377, sync dist 306.79
    delay 0.61 msec, offset -1.8279 msec, dispersion 4.73
    precision 2**22, version 4
    org time D8E6B23E.726564BD (10:39:26.446 AEST Sun Apr 26 2015)
    rec time D8E6B23E.72FFC6BD (10:39:26.449 AEST Sun Apr 26 2015)
    xmt time D8E6B23E.72CFC2A8 (10:39:26.448 AEST Sun Apr 26 2015)
    filtdelay =     0.71    0.68    0.71    0.68    0.72    0.73    0.70    0.61
    filtoffset =   -1.99   -1.97   -1.96   -1.97   -1.97   -1.97   -1.90   -1.82
    filterror =     0.00    0.99    1.93    2.91    3.90    4.87    5.82    6.81
    minpoll = 6, maxpoll = 10

  • Cisco 3750X -- 10G uplink - Can be used as access port?

    Dear All,
    I have small question, I am planning for Cisco 3750X with 10G SFP+ service module. I want to know that whether it can be used as Access Ports connecting to server as this is mostly used as uplink port.
    Thank You,
    Abhisar.

    Disclaimer
    The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.
    Liability Disclaimer
    In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.
    Posting
    Well if you want to connect anything with 10g to a 3750X, you're limited to using a module with 10g ports. 
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  • Cisco 3750x 24 port poe switch single port is faulty.

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    Duplicate posts.  
    Go here:  http://supportforums.cisco.com/discussion/12187366/cisco-3750x-24-port-poe-switch-failure

  • Cisco 3750x 24 port poe switch failure

    what is the chance of cisco 3750x 24 port poe switch failure? is backup necessary for this ? please answer me in details.

    If you have a Cisco switch with, at least, one faulty port you RMA the appliance.  
    There is nothing more detailed than that.

  • Native VLAN on Cisco 3750x vs Cisco 2960S

    Hi,
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    My question is when i connect router with cisco 2960s I config interface Gi1/0/1 as a trunk. everything work fine, I can ping from router to switch(172.16.29.2).
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    Hi John
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