A while back, I tasked one of my team members to update the NTP servers used in one of our datacenters. We were using standard pool NTP services and decided to move away from them for various reasons. We found that stable time was more important than accurate time, and the pools definitely didn't add stability. NTP uses UDP by default, and we wanted to turn off/ACL-off UDP in certain networks. So we grabbed a few CDMA-based time servers off of Ebay, fronted them with our typical Juniper SRX firewalls, and set up clients to use the SRX's as time sources.
After setting up a few devices, this employee suggested, "Hey why don't we set this up on a loopback and anycast it?" I thought about it for a second, something else came up, we moved on, and the suggestion was forgotten (by both of us). We had not finished moving everything from flat, layer 2 networks to a true Clos L3LS setup, so the timing wasn't just right. After finishing the L3LS migration, I looked at this again......and we're very happy with the results.
A Creole coonass just trying to get by. I live in San Francisco and work as a digital plumber for the joint that runs this thing. (Square/Weebly) Thoughts are mine, not my company's.