Refer to the exhibit. A network engineer must deny access from spoofed addresses to the LAN. The edge router currently has two active BGP sessions established with Tier 1 ISP_A. Due to asymmetric…

The `ip verify unicast source reachable-via tx` syntax is incorrect or refers to a non-standard or deprecated mode; furthermore, a strict check (implied by `tx` or `rx`) would drop legitimate traffic in an asymmetric routing environment.

The command `ip verify unicast source reachable-via` is incomplete and lacks the necessary mode keyword (`any`, `rx`, `exists-only`) to configure uRPF properly.

The `ip verify unicast source reachable-via any` command configures Unicast Reverse Path Forwarding (uRPF) in loose mode on interface FA0/1. This mode checks if a route to the source IP address exists in the routing table via any interface, making it suitable for environments with asymmetric routing where ingress and egress paths may differ, while still dropping packets with spoofed source IPs that are not routable.

The `ip verify unicast source reachable-via both` syntax is incorrect; `both` is not a valid mode for uRPF configuration.

Similarly, `ip verify unicast source reachable-via any` on interface FA0/0 applies uRPF in loose mode to the other internet-facing interface. Implementing uRPF in `any` mode on both external interfaces (FA0/0 and FA0/1) ensures comprehensive protection against source IP spoofing without disrupting legitimate traffic that traverses asymmetric routes.