1flow ah out proto udp from 1.1.1.1 port ntp to 2.2.2.2 peer 2.2.2.2 type require 2flow ah in proto udp from 2.2.2.2 to 1.1.1.1 port ntp peer 2.2.2.2 type require 3flow ah out proto udp from 1.1.1.1 port ntp to 2.2.2.2 peer 2.2.2.2 type require 4flow ah in proto udp from 2.2.2.2 to 1.1.1.1 port ntp peer 2.2.2.2 type require 5