Hi. Yes I'm making a last call comment on a document I edit:-) During discussion of another document )(draft-ietf-karp-crypto-key-table), a routing directorate review brought up the concern that we don't talk about time synchronization. Without time synchronization, the wrong keys can be selected in certain circumstances. In some cases, time synchronization is required for replay detection, although that is rare for routing protocols. Those involved in the discussion of time synchronization and draft-ietf-karp-crypto-key-table believed that draft-ietf-karp-ops-model is a better place for a discussion of time synchronization than draft-ietf-karp-crypto-key-table. So, I'd like to propose the following text be added to security considerations: <t>Close synchronization of time can impact the security of routing protocols in a number of ways. Time is used to control when keys MAY bxegin being used and when they MUST NOT be used any longer as described in <xref target="i-d.ietf-karp-crypto-key-table"></xref>. Routers need to have tight enough time synchronization that receivers permit a key to be used prior to the first use of that key or availability will be impacted. If time synchronization is too loose, then a key can be used beyond its intended lifetime. The Network Time Protocol (NTP) can be used to provide time synchronization. For some protocols, time synchronization is also important for replay detection.