Access Control List Directions "In" and "Out"

[lutheran1971]

Sorry about the elementary nature of this question. When an ACL is applied to say a VLAN's SVI in this way;

interface Vlan111

ip address 10.10.10.10 255.255.255.0

ip access-group 111 in

or

ip access-group 112 out

..does the traffic direction "in" refer to traffic towards the SVI from Vlan111 only or also towards the networks and associated SVIs from other VLANs across the routing engine as well? Similarly, would "out" refer to traffic towards VLAN 111 only from (through) it's SVI or also towards other SVI's across the routing engine? Thank you for any information.

[lutheran1971]

Sorry the first sentence in my last paragraph should read;

..does the traffic direction "in" refer to traffic towards the SVI from Vlan111 only or also towards it from the networks and associated SVIs from other VLANs across the routing engine as well?

[Richard Burts]

Bob

The direction in which the access list is applied is from the prespective of the router/switch. So an access list applied "in" will filter traffic from the devices attached in that VLAN coming into the router/switch to be routed. And an access list applied "out" will filter traffic from other VLANs routed out that VLAN to the attached devices.

HTH

Rick

[lutheran1971]

Thank you Rick!