You are using BGP-4 in the WAN between AS1, AS2, and AS3. Describe in plain text or as BGP-4 policy statement how you would:
a. Permit AS3 to communicate with AS1 but not allow AS2 to communicate with AS1.
b. Allow both AS2 and AS3 Internet access through AS1 only between 6 p.m. and 6 a.m. EST each night