To identify the most accurate stratum, think of the stratum as the number of 'hops' from the master time source.
ie: your publisher server is sync'd to your internal router; your internal router is sync'd to your Internet router; your Internet router is sync'd to a master time source on the net; that's three stratum 'hops' right there. A lowest 'root' master time source would use stratum 0. ie: Master = stratum 0 >>> internet router = stratum 1 >>> internal router = stratum 2 >>> publisher = stratum 3 At this point, any device syncing to the publisher would use stratum 4. (or higher) Any device syncing to the internal router would use stratum 3 (or higher)....etc. (of course, your internet router may or may not sync to a stratum 0 master; it could be a higher stratum which in that case you'd increment your stratum numbers down the line appropriately) greg -----Original Message----- From: ccie_voice-boun...@onlinestudylist.com [mailto:ccie_voice-boun...@onlinestudylist.com] On Behalf Of bkvalent...@gmail.com Sent: Friday, July 09, 2010 7:07 AM To: cisco voip; Mark Holloway Cc: OSL osl Subject: Re: [OSL | CCIE_Voice] NTP A router that has "ntp server" configured also acts as a server. You don't need ntp master to act as a server. Brian ----- Reply message ----- From: "cisco voip" <voip.ccieci...@gmail.com> Date: Thu, Jul 8, 2010 10:42 pm Subject: [OSL | CCIE_Voice] NTP To: "Mark Holloway" <m...@markholloway.com> Cc: "OSL osl" <ccie_voice@onlinestudylist.com> But "ntp master" command is necessary for the router to be able to be ntp server for anyone else. i agree about stratum chain, but without ntp master command publisher should not be able to get its clock. you can check show ntp associations on the router, after ntp master command only it will show you the local interface. now if you want to use the stratum to be 1 more from whatever the stratum is on actual source, you do not need stratum command, for anything else you need that commnd On Fri, Jul 9, 2010 at 4:42 AM, Mark Holloway <m...@markholloway.com> wrote: > Cool, thanks Graham and Randall. > > On Jul 8, 2010, at 4:11 PM, Graham Hopkins wrote: > > > Default stratum is 8 so a simple ntp master will work > > > > Graham > > > > On 8 Jul 2010, at 23:59, Mark Holloway <m...@markholloway.com> wrote: > > > >> Yikes, I meant "ntp master stratum X" not "ntp server stratum X" > >> > >> On Jul 8, 2010, at 3:57 PM, Mark Holloway wrote: > >> > >>> If a router (for example, HQ) is configured with the "ntp server > x.x.x.x" command to sync time from another source, but I want another > device (such as PUB) to get its time from the HQ router, do I also > need to configure the HQ router with "ntp server stratum X" or can UCM > simply get the time sync from HQ without the stratum command? > >>> _______________________________________________ > >>> For more information regarding industry leading CCIE Lab training, > please visit www.ipexpert.com > >> > >> _______________________________________________ > >> For more information regarding industry leading CCIE Lab training, > please visit www.ipexpert.com > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, > please visit www.ipexpert.com > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
