direction
Direction of traffic.
Syntax
It is important to note that this parameter does not alter the behaviour of the source and destination IP address parameters. If a rule's source IP address corresponds to the local system, a value of 'inbound' would be a contradiction in terms, and the rule itself would be meaningless. The same holds true for a value of 'outbound' in a rule where the destination IP address corresponds to the local system; the rule would never apply to anything.
For instance, on a firewall whose local IP address is 10.4.3.2, the rule:
permit 0.0.0.0 0.0.0.0 10.4.3.2 0.0.0.0 all any 0 any 0 both both outboundis useless, since traffic whose final destination is the local system can by definition never be 'outbound'.
Consequently, this parameter only has practical use on a router, when the firewall system is neither the source nor the destination.
To avoid confusion, it is generally simplest for non-routing firewalls to set this parameter to 'both' for all rules.