Refer to the exhibit. A network administrator has configured a standard ACL to permit only the two LAN networks attached to R1 to access the network that connects to R2 G0/1 interface. When following the best practices, in what location should the standard ACL be applied?

Applying the standard ACL on R2 G0/1 outbound means that the ACL is placed on the G0/1 interface of router R2, and it is configured to filter traffic as it leaves that interface and goes towards its destination. In this case, the destination is the network connected to R2’s G0/1 interface.

Here’s an explanation of how this setup works:

1. Traffic Flow: When devices from the LAN networks attached to R1 (e.g., H1 and H2) attempt to communicate with devices in the network connected to R2’s G0/1 interface, the traffic flows from R1 to R2 via R2’s G0/1 interface.
2. Outbound ACL: Placing the ACL outbound on R2’s G0/1 interface means that the ACL is applied to this interface’s outbound traffic path, which is the traffic leaving the G0/1 interface. The ACL is evaluated when the traffic is leaving R2 and heading towards its destination.
3. Filtering Criteria: The standard ACL configured on R2’s G0/1 outbound interface should contain rules that permit specific source IP addresses (belonging to the LAN networks of R1) and deny other source IP addresses. This effectively filters out unwanted traffic at the exit point of R2.
4. Permitted Traffic: Traffic from R1’s LAN networks that matches the ACL’s permit rules is allowed to pass through R2’s G0/1 interface and reach the destination network connected to G0/1.
5. Denied Traffic: Traffic from R1’s LAN networks that does not match the ACL’s permit rules will be denied at R2’s G0/1 interface and will not reach its destination.
6. Effectiveness: This configuration allows you to control which traffic from R1’s LAN networks is allowed to access the network connected to R2’s G0/1 interface. It effectively filters the traffic as it exits R2, ensuring that only permitted traffic can reach its destination.

While applying ACLs outbound on an interface can be a valid configuration, it’s important to ensure that the ACL rules are correctly defined to achieve the desired security and access control objectives for your network.