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This option proposes: Inspect local and remote BFD configured minima, actual negotiated intervals, multiplier values, CPU pressure and observed detection timestamps. It addresses the different topic BFD detection multiplier and negotiated timers, not the directly tested BFD rapid session detection and routing protocol association failure in the stated incident (An operator adds a BFD peer session on a new WAN circuit but the associated BGP route stays active after a tested BFD failure because the protocol binding was omitted.).

This option proposes: Review VLAN IGMP query source, version, group reports, membership timers and the downstream interface in multicast routing state. It addresses the different topic IGMP querier membership reports and group timeout, not the directly tested BFD rapid session detection and routing protocol association failure in the stated incident (An operator adds a BFD peer session on a new WAN circuit but the associated BGP route stays active after a tested BFD failure because the protocol binding was omitted.).

This option proposes: Compare host ARP for the virtual gateway, advertised VRRP virtual MAC, switch forwarding table, master state and test traffic during takeover. It addresses the different topic VRRP virtual MAC and endpoint ARP continuity, not the directly tested BFD rapid session detection and routing protocol association failure in the stated incident (An operator adds a BFD peer session on a new WAN circuit but the associated BGP route stays active after a tested BFD failure because the protocol binding was omitted.).

That option concerns VRRP interface tracking and controlled preemption. That follows from the targeted Recommended action: Use Bidirectional Forwarding Detection to provide rapid validated failure indications to a supported routing or redundancy protocol.

That option concerns VRRP master election priority and tie breaks. That follows from the targeted Recommended action: Use Bidirectional Forwarding Detection to provide rapid validated failure indications to a supported routing or redundancy protocol.

That option concerns Huawei firewall NAT and address translation context. That follows from the targeted Recommended action: Use Bidirectional Forwarding Detection to provide rapid validated failure indications to a supported routing or redundancy protocol.

This option proposes: Require a client to change to a new application login and IP subnet after every intra-campus AP roam because wireless roaming is presumed equivalent to a new WAN circuit. It addresses the different topic Wireless roaming mobility and session continuity, not the directly tested BFD rapid session detection and routing protocol association failure in the stated incident (An operator adds a BFD peer session on a new WAN circuit but the associated BGP route stays active after a tested BFD failure because the protocol binding was omitted.).

This option proposes: Assume two routers can each configure a different virtual IP for the same VRRP group and still present one consistent default gateway to hosts. It addresses the different topic VRRP master election priority and tie breaks, not the directly tested BFD rapid session detection and routing protocol association failure in the stated incident (An operator adds a BFD peer session on a new WAN circuit but the associated BGP route stays active after a tested BFD failure because the protocol binding was omitted.).

This option proposes: Require every desktop to change its configured default gateway to the backup router's physical interface address immediately after each VRRP election. It addresses the different topic VRRP virtual MAC and endpoint ARP continuity, not the directly tested BFD rapid session detection and routing protocol association failure in the stated incident (An operator adds a BFD peer session on a new WAN circuit but the associated BGP route stays active after a tested BFD failure because the protocol binding was omitted.).

This option proposes: Use Bidirectional Forwarding Detection to provide rapid validated failure indications to a supported routing or redundancy protocol. It addresses the different topic BFD rapid session detection and routing protocol association, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.).

This option proposes: Configure VRRP priority tracking with suitable preemption behavior so loss of upstream connectivity changes the preferred gateway. It addresses the different topic VRRP interface tracking and controlled preemption, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.).

This option proposes: Trace an enterprise wireless AP's registration to its access controller and the separation of management from user traffic in supported forwarding modes. It addresses the different topic Large campus WLAN AC AP and CAPWAP architecture, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.).

This option proposes: An NSSA permits its local ASBR to originate type 7 external LSAs that can be translated to type 5 by an eligible ABR, while incoming external type 5 advertisements are not flooded into the NSSA. It addresses the different topic NSSA type seven translation and default routing, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.).

This option proposes: VRRP uses a virtual router identity and virtual MAC per IPv4 group to preserve a stable next-hop identity across master changes; correct failover still requires matching VLAN, neighbor learning and eligible router state. It addresses the different topic VRRP virtual MAC and endpoint ARP continuity, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.).

This option proposes: VRRP provides a shared virtual default-gateway identity, generally electing a higher-priority router as master while tie-breaking rules and address-owner behavior are relevant; hosts use the virtual address rather than the physical router selected by a static setting. It addresses the different topic VRRP master election priority and tie breaks, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.).

This option proposes: Inspect the received AS_PATH, origin AS, eBGP neighbor AS, policy additions and route-selection evidence before changing prepend counts. It addresses the different topic BGP AS_PATH path-vector loop prevention, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.). The better discriminating check for this case is: Inspect local and remote BFD configured minima, actual negotiated intervals, multiplier values, CPU pressure and observed detection timestamps. The targeted correction is: Calculate or verify the practical failure-detection threshold from BFD transmit intervals, advertised receive intervals and the detect multiplier.

This option proposes: Inspect BFD discriminator and session state, timer negotiations, neighbor addresses, routing protocol binding and actual packet-loss observations. It addresses the different topic BFD rapid session detection and routing protocol association, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.).

This option proposes: Compare host ARP for the virtual gateway, advertised VRRP virtual MAC, switch forwarding table, master state and test traffic during takeover. It addresses the different topic VRRP virtual MAC and endpoint ARP continuity, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.).

That option concerns OSPF adjacency prerequisites and mismatched parameters. That follows from the targeted action: Calculate or verify the practical failure-detection threshold from BFD transmit intervals, advertised receive intervals and the detect multiplier.

That option concerns VRRP master election priority and tie breaks. That follows from the targeted action: Calculate or verify the practical failure-detection threshold from BFD transmit intervals, advertised receive intervals and the detect multiplier.

That option concerns BFD rapid session detection and routing protocol association. That follows from the targeted action: Calculate or verify the practical failure-detection threshold from BFD transmit intervals, advertised receive intervals and the detect multiplier.

This option proposes: Diagnose a multicast drop by checking reverse path forwarding against the packet's source rather than only validating the destination group. It addresses the different topic Multicast reverse path forwarding checks, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.).

This option proposes: Inspect VRRP group ID, configured virtual IP, device priorities, master/backup state and advertisements on both routers. It addresses the different topic VRRP master election priority and tie breaks, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.).

This option proposes: Use standard BGP communities and import/export policy to label route groups and apply intended traffic-engineering behavior. It addresses the different topic BGP community tagging and route-policy control, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (An enterprise sets tiny BFD intervals across low-end branch routers and sessions repeatedly flap during backup windows although actual packet forwarding remains healthy.).

This option proposes: Inspect compatible IS-IS NET area IDs, interface levels and authentication before changing a routing process after adjacency failure. It addresses the different topic IS-IS area addresses and adjacency prerequisites, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (A backbone change request claims a 300 ms failure threshold, but the operating BFD session uses a 100 ms negotiated interval and a detect multiplier of five.).

This option proposes: Use Bidirectional Forwarding Detection to provide rapid validated failure indications to a supported routing or redundancy protocol. It addresses the different topic BFD rapid session detection and routing protocol association, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (A backbone change request claims a 300 ms failure threshold, but the operating BFD session uses a 100 ms negotiated interval and a detect multiplier of five.).

This option proposes: Analyze Virtual Router Redundancy Protocol master election using priorities and the virtual router ID instead of a router's physical interface address alone. It addresses the different topic VRRP master election priority and tie breaks, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (A backbone change request claims a 300 ms failure threshold, but the operating BFD session uses a 100 ms negotiated interval and a detect multiplier of five.).

This option proposes: VRRP uses a virtual router identity and virtual MAC per IPv4 group to preserve a stable next-hop identity across master changes; correct failover still requires matching VLAN, neighbor learning and eligible router state. It addresses the different topic VRRP virtual MAC and endpoint ARP continuity, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (A backbone change request claims a 300 ms failure threshold, but the operating BFD session uses a 100 ms negotiated interval and a detect multiplier of five.).

This option proposes: BFD exchanges lightweight control packets to test bidirectional forwarding paths and can notify registered clients such as routing processes; it is not itself a route-distribution protocol or a guarantee of link-physical failure. It addresses the different topic BFD rapid session detection and routing protocol association, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (A backbone change request claims a 300 ms failure threshold, but the operating BFD session uses a 100 ms negotiated interval and a detect multiplier of five.).

This option proposes: Rapid Spanning Tree Protocol reduces convergence time by exchanging proposal/agreement information on eligible links and maintaining alternate paths, while only the root and designated forwarding ports should carry traffic in a stable tree. It addresses the different topic RSTP port roles and rapid convergence, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (A backbone change request claims a 300 ms failure threshold, but the operating BFD session uses a 100 ms negotiated interval and a detect multiplier of five.).

This option proposes: Inspect the received AS_PATH, origin AS, eBGP neighbor AS, policy additions and route-selection evidence before changing prepend counts. It addresses the different topic BGP AS_PATH path-vector loop prevention, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (A backbone change request claims a 300 ms failure threshold, but the operating BFD session uses a 100 ms negotiated interval and a detect multiplier of five.). The better discriminating check for this case is: Inspect local and remote BFD configured minima, actual negotiated intervals, multiplier values, CPU pressure and observed detection timestamps. The targeted correction is: Calculate or verify the practical failure-detection threshold from BFD transmit intervals, advertised receive intervals and the detect multiplier.

This option proposes: Inspect BFD discriminator and session state, timer negotiations, neighbor addresses, routing protocol binding and actual packet-loss observations. It addresses the different topic BFD rapid session detection and routing protocol association, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (A backbone change request claims a 300 ms failure threshold, but the operating BFD session uses a 100 ms negotiated interval and a detect multiplier of five.).

This option proposes: Review the monitored uplink state, tracked priority decrement, master/backup advertisements, preemption settings and return-path reachability. It addresses the different topic VRRP interface tracking and controlled preemption, not the directly tested BFD detection multiplier and negotiated timers failure in the stated incident (A backbone change request claims a 300 ms failure threshold, but the operating BFD session uses a 100 ms negotiated interval and a detect multiplier of five.).