# Allow listing traffic

Allow listing means defining a list of IP addresses that must never be block listed.

Allow listing is implemented by following general Access rule design principles. Block listing applies only at the position of the block listing Access rules in the policy. Connections that have already been allowed or discarded before the block listing rules are not affected by block listing. If an Access rule allows a connection, an Access rule that refers to the block list further down in the policy cannot block list the connection.