NTP peering and and client...at the same time?

[R_Acuti]

I've a customer who wants to peer some of our network devices so that in case of a loss of our authoritative NTP sources, they will remain synchronized with each other. These devices also act as NTP servers to every device downstream from them.

In essence, these peers will occupy all three states- server, client and peer. 

Is this possible? Does it even make sense to do so?

The Cisco NTP Best Practices white paper calls out 3 architectures- flat peer, hierarchy and star. It seems like my customer is asking for a merging of the first two.

[Jon Marshall]

Apologies if I am pointing out something you have already understood but you can configure one of the peer group to be an NTP master just make sure, as Rick says, it is a higher stratum and then what your customer wants is exactly what will happen. 

Please ignore if I am stating the obvious. 

Jon