When applying an ACL to a router interface, which traffic is designated as outbound?
- Traffic that is coming from the source IP address into the router.
- Traffic that is leaving the router and going toward the destination host.
- Traffic for which the router can find no routing table entry.
- Traffic that is going from the destination IP address into the router.
Explanation: The designation of traffic as "inbound" or "outbound" is determined by the direction it flows relative to a specific router interface:
- Outbound ACLs: These process traffic that is leaving the router through an interface and traveling toward its destination. When a packet is designated as outbound, the router has already performed a routing lookup to determine the correct exit interface; the packet is only then tested against the outbound ACL before being forwarded.
- Inbound ACLs: These process incoming packets that are entering the router through an interface before they are routed to an outbound interface. This is considered more efficient because it prevents the router from wasting resources on a routing lookup for a packet that will ultimately be denied.
Therefore, outbound traffic is specifically the data stream that has been successfully routed and is now exiting the device's interface toward the destination host.
Related exam: Modules 14 – 16: Checkpoint Exam: Network Security Answers (CCNP ENCOR v9)
