If OMP graceful restart is 24 hours, what IPsec rekey timer must be configured?

For OMP graceful restart to function correctly, the IPsec rekey timer must be set to a value less than the OMP graceful restart timer. This ensures that the underlying IPsec tunnels, which carry OMP traffic, do not rekey and disrupt OMP before the graceful restart period expires. A rekey event would cause OMP to reset, defeating the purpose of graceful restart. In this scenario, with an OMP graceful restart of 24 hours, an IPsec rekey timer of 12 hours is appropriate as it is less than 24 hours. Setting it to 6 hours would also work but is unnecessarily frequent. 36 hours and 48 hours are incorrect because they are longer than the OMP graceful restart timer, which would lead to OMP instability during graceful restart.