I am using a Cisco 2611 as an NTP master at stratum 2, and syncing other 2611's off this at stratum 3 running IOS V.12 and over. The connectivity between them is by a mixture of ATM and Frame Relay. The problem I have is that if I make any changes to the clock settings on the master, some of the other routers either lose sync and dont get it back, or keep sync but dont update their time.