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Network configuration and policy updates occur frequently, and must be performed in a way that minimizes transient effects caused by intermediate states of the network. It has been shown that accurate time can be used for coordinating network-wide updates, thereby reducing temporary inconsistencies. However, this approach presents a great challenge; even if network devices have perfectly synchronized clocks, how can we guarantee that updates are performed at the exact time for which they were scheduled? In this paper we present a practical method for implementing accurate time-based updates, using TIMEFLIPs. A TimeFlip is a time-based update that is implemented using a timestamp field in a Ternary Content Addressable Memory (TCAM) entry. TIMEFLIPs can be used to implement Atomic Bundle updates, and to coordinate network updates with high accuracy. We analyze the amount of TCAM …