Question 370
A FortiGate internet policy is enabled but client traffic fails because the WAN default route still points at the old ISP gateway after circuit replacement. Which diagnostic evidence should the FortiGate administrator check FIRST?
Explanation
Correct Answer
Inspect routing monitor, static route enablement, interface link, neighbor ARP, gateway reachability, destination prefixes and diagnostic route lookups. This distinguishes the relevant FortiGate device, session or controller evidence. An installed firewall policy cannot supply a missing route; administrative distance, route status and usable next-hop reachability affect forwarding. The corresponding action is: Configure valid FortiOS static and default routes for the approved next hops and outgoing interfaces, validating that gateways are reachable in the intended routing instance. Scenario: A FortiGate internet policy is enabled but client traffic fails because the WAN default route still points at the old ISP gateway after circuit replacement.
Incorrect Answers
Inspect the active route table, equal-prefix candidates, distance values, priorities, ECMP status, next-hop reachability and matching interface state. This diagnostic is related to Static route priority, administrative distance and ECMP design rather than the controlling evidence for this scenario. Examine instead: Inspect routing monitor, static route enablement, interface link, neighbor ARP, gateway reachability, destination prefixes and diagnostic route lookups. Scenario: A FortiGate internet policy is enabled but client traffic fails because the WAN default route still points at the old ISP gateway after circuit replacement.
Inspect FIB route selection, source and destination prefixes, reverse path, configured policy routes, ingress interface and paired packet traces. This diagnostic is related to Routing table and reverse-path asymmetric connectivity analysis rather than the controlling evidence for this scenario. Examine instead: Inspect routing monitor, static route enablement, interface link, neighbor ARP, gateway reachability, destination prefixes and diagnostic route lookups. Scenario: A FortiGate internet policy is enabled but client traffic fails because the WAN default route still points at the old ISP gateway after circuit replacement.
Examine source/destination firewall policy, SD-WAN zone, NAT behavior, explicit policy routes, application signature, health check and session egress. This diagnostic is related to SD-WAN interactions with firewall policies and source-specific routes rather than the controlling evidence for this scenario. Examine instead: Inspect routing monitor, static route enablement, interface link, neighbor ARP, gateway reachability, destination prefixes and diagnostic route lookups. Scenario: A FortiGate internet policy is enabled but client traffic fails because the WAN default route still points at the old ISP gateway after circuit replacement.