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Time Sync - SNTP and Summer Time

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rihatum
Occasional Advisor

Time Sync - SNTP and Summer Time

Hi All,

We have 5 Switches, 2 x 2510G 24 Port and 3x2510 48 Port switches (layer2)

I set up the SNTP server address as one of our windows 2003 server (not a dc), time was sycing fine, since summer time change here in the UK (GMT) the time on the switches haven't synced / updated - it has on the windows 2003 server itself.

Do I need to reboot the switches in order to sync time ?

which command would one use to safely reboot the switch - "reload" ?

Thanks and Regards
9 REPLIES
MultiNet_1
Occasional Visitor

Re: Time Sync - SNTP and Summer Time

No, Rebooting will not solve it. You need to set the offset of the Daylight saving time to 60 minutes between the last Sunday of March and the last Sunday of October.
rihatum
Occasional Advisor

Re: Time Sync - SNTP and Summer Time

Hi Multinet,

Thanks for your prompt reply, how can we set the offset ? how do we calculate it ?

kind regards
Mohammed Faiz
Honored Contributor
Solution

Re: Time Sync - SNTP and Summer Time

Have you set the time zone with the command "time daylight-time-rule Western-Europe".
Also check your poll interval with "show sntp".

Yes "reload" is what you would use to reboot a switch (but you don't need to in this case).
rihatum
Occasional Advisor

Re: Time Sync - SNTP and Summer Time

Hi Fiaz,

Thank you again for your reply on this thread, here is the show sntp output :

SNTP Configuration

Time Sync Mode: Sntp
SNTP Mode : Unicast
Poll Interval (sec) [720] : 720


IP Address Protocol Version
-------------- ----------------
192.168.1.253 3

--------------------

Now, we are based in the United Kingdom (England), so what shall I input after :
"time daylight-time-rule western-europe"

thanks and regards
Rihatum
Mohammed Faiz
Honored Contributor

Re: Time Sync - SNTP and Summer Time

Hi,

The default value is fine (so just press enter).
For reference the default for "western-europe" is :

â ¢ Begin DST at 2am the first Sunday on or after March 23rd.
â ¢ End DST at 2am the first Sunday on or after October 23rd.
rihatum
Occasional Advisor

Re: Time Sync - SNTP and Summer Time


Hi Fiaz,

Thank you for explaining ; I went into configure terminal and typed the following command :

Switch-2(config)# time daylight-time-rule western-europe

and then the time sync, I didn't had to specify any dates or anything else just the command and enter.

do I need to do anyhing else or is this ok ?

Kind Regards
Mohammed Faiz
Honored Contributor

Re: Time Sync - SNTP and Summer Time

Hi (it's Mohammed btw :) )

No, that's fine. At some point in the next 12 minutes (720 seconds) it should update.
rihatum
Occasional Advisor

Re: Time Sync - SNTP and Summer Time

Hi Mohammad,

Thanks for your assistance on all my threads so far.

a Quick question, I haven't rebooted the switches since install (more then 60days).

there are quite a few broadcast detected on ports for e.g. broadcast detected on port 13 (same ports almost everyday in the morning) when the user switches on the pc - I guess.

Also, I noticed CRC / Alignment Errors as well

Any thoughts on that - what should be done to get rid of these ?

Mohammed Faiz
Honored Contributor

Re: Time Sync - SNTP and Summer Time

Hi rihatum,

Best to start a new thread for this so everyone can contribute :)