07-15-2009 04:32 AM - edited 03-06-2019 06:46 AM
Hello All
I want to use my core switch 192.168.1.1 as a NTP server for all other swithces on my network.Is there any way to do that ?
Thx
Ersin
07-15-2009 04:39 AM
Hello Ersin,
switch 192.168.1.1 has to use the NTP master command but you should sync it with a NTP source for example over the internet.
all other devices will have
ntp server 192.168.1.1
Some old routers like C4700 had an on board calendar and are handy for this
be aware that NTP sync requires time (minutes)
and udp port 123 needs to be permitted
Hope to help
Giuseppe
07-15-2009 04:55 AM
I did not get the ntp source part.May I use the core switch as a source ? What command needs to be typed on that switch
07-15-2009 05:08 AM
Ersin
If you configure your core switch to learn NTP time from some external source of NTP then your core switch can function as an NTP server to the other devices in your network. If your core switch does not learn NTP time from an external source then you can configure it to function as an NTP server by configuring it as ntp master. The commands that you would type vary depending on whether your core switch is CatOS or IOS. Which is it?
HTH
Rick
07-15-2009 05:26 AM
My core switch has IOS.I do not know which source to use ? Domain controller maybe but how ?
07-15-2009 06:52 AM
There is probably nothing in your server/switch environment that will function as a good NTP server, their clocks aren't accruate enough. You need a stratum 2 or stratum 1 source. Here is one of may lists of Public NTP servers.
http://support.microsoft.com/kb/262680
You allow the port in, and synch to that. then your "inside" server can provide NTP to the rest of your network. See Guiseppes example above (he is never wrong)
more light reading: http://www.cisco.com/en/US/tech/tk869/tk769/technologies_white_paper09186a0080117070.shtml
IOS config guide:http://www.cisco.com/en/US/docs/ios/netmgmt/configuration/guide/nm_basic_sys_manage_ps6922_TSD_Products_Configuration_Guide_Chapter.html
07-15-2009 07:45 AM
Basicly what I did and worked
Go to core switch
-set time and date by "clock" command
-type ntp master command
-Go to edge switches and type
-ntp server
ıf you have vlans type vlan default
gateways for the IP address.
Only thing this is manual system make sure your core switch works fine :)
Regards
Ersin
07-15-2009 07:57 AM
One thing is interesting that I wanted to share ....
I defined my core switch as a ntp master
my 2 dist switches also using coreswitch for getting clock info.VLANs which were defined on dist switches connected to some edge switches.When I type
ntp server vlandefaultgatewway
it works but funny thing is that ;
that VLAN defined on dist switch even dist switch is not ntp master edge switches are getting the time from dist switches or core switch ????
07-15-2009 08:52 AM
keep in mind, your clock is only as good as your source.
07-15-2009 10:32 PM
But as I said ;
I did not get how did it happen ?
ntp master is my core
edge switches connected to Dist switch and VLANs are defined on Dist switches and on edge switches I typed
ntp server
So even the server is Core switch edge switches get the clock from Dist switches ? any idea ?
Regards
Ersin
07-16-2009 01:43 PM
what are your NTP assocications?
07-16-2009 10:21 PM
I did not get your question...
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