Hi,

I have a question about NTP. We want to setup our core switches as ntp master for our network.

We have three data centers.

Site A : Two Nexus as core

Site B : two Nexus as core

Site C : two 6800 (in VSS, so it's kind of one logical switch) as core

In site A and B, we have servers. In site C, we have servers and clients.

We want our network devices (servers, clients, etc) to get their time from these switches.

I was thinking about setting external ntp servers from the internet on these switches and connect them as ntp peers.

Question 1 :

Should we connect all cores switches (from all three sites) as "ntp peers" all together (kind of full mesh setup) ?

Or

Should each site have their local switches connected as peers ? Except Site C, which a one logical switch...

Question 2 :

Should all clients/servers be configured to use all ntp servers (so their list of ntp servers will be all switches from all sites over WAN) ?

Or

Clients/servers should only have their local ntp servers configured  ?

Question 3 :

Should all core switches acting as ntp master have their clock sync with ntp servers on the internet ?

Or

Only some ntp masters should be connected to the internet for external sync ? If so, would you chose a dedicated site for this or one switches in each site ?

Thank you and sorry for my english !