Topic183 problems· 2 reviewed

Routing And Failover Paths

183 incident problems about Routing And Failover Paths. Start with the reviewed ones.

All problems (183)

NETWORK-133An IP SLA object track recovers immediately, but without hysteresis the WAN edge oscillates on every brief probe successThe failover design is correct in principle, yet recovery logic is too eager for the quality of the circuit.NetworkAdvanced17 minPro NETWORK-096HSRP preempt delay is shorter than upstream route convergence and gateway flaps twice on recoveryFailover succeeds initially, but recovery creates another outage because the active gateway returns before its upstream dependencies are ready.NetworkAdvanced17 minPro NETWORK-100Anycast DNS stays reachable but one site serves stale zone data after an AXFR policy changeThe service appears up globally, yet answers diverge because one anycast site stopped receiving zone transfers under the new policy.NetworkAdvanced18 minPro NETWORK-086IP SLA tracks the wrong probe target and withdraws the primary path during a healthy application incidentFailover triggers exactly as configured, but the chosen probe target does not represent the real application health and causes an unnecessary routing shift.NetworkAdvanced18 minPro NETWORK-089OSPF adjacency forms but area type mismatch suppresses the LSAs needed by the branch routeNeighbor status looks correct, yet the expected route never appears because one side treats the area differently and filters critical LSA propagation.NetworkAdvanced18 minPro NETWORK-093OSPF adjacency remains full but the summary route hides the more specific path needed for policy routingThe protocol is healthy, yet the application path fails because route summarization obscures the specific destination the policy logic depends on.NetworkAdvanced19 minPro NETWORK-078Anycast service becomes unstable after an IGP cost change moves stateful clients across sitesThe anycast design still advertises correctly, but a cost change shifts clients to another site that does not hold the expected state continuity.NetworkAdvanced21 minPro NETWORK-090EVPN MAC mobility is detected but the dampening timer keeps traffic pinned to the old leafThe control plane sees the move, yet data still breaks because mobility dampening delays acceptance of the new location longer than the workload can tolerate.NetworkAdvanced22 minPro NETWORK-138A local preference change is present in policy, but without soft reconfiguration the edge never reevaluates existing paths until a clearThe route-map is correct, yet the live table still reflects yesterday's decision because policy reevaluation never happened.NetworkAdvanced16 minPro NETWORK-155A routing summary is correct in normal conditions, but when the only specific route fails the summary still attracts traffic into a black holeAggregation reduced table size, yet it also masked the absence of any viable child route.NetworkIntermediate16 minPro NETWORK-393A static summary route is valid while the tracking object for the real downstream next hop was repointed to an interface that stays up during failure during a staged decommissionThe summary remains installed long after the useful path is gone. The service still works through the primary path, but one dependency only fails when the old component is finally drained away.NetworkIntermediate16 minPro NETWORK-109Gateway tracking monitors only the interface state while the upstream SLA probe is already failingThe local interface is up, but the default gateway should have failed over earlier because the real dependency is beyond the first-hop link.NetworkAdvanced16 minPro NETWORK-345A BGP edge prefers the right path (Rollout Stuck)A BGP edge prefers the right path (Rollout Stuck) focuses on Routing And Failover Paths and asks the reader to isolate Rollout Stuck in Cisco. 실무에서는 rollout-stuck 이슈를 볼 때 DNS, 라우팅, ACL/방화벽, 목적지 응답을 계층별로 잘라서 확인하면 장애 구간을 훨씬 빠르게 좁힐 수 있습니다.NetworkAdvanced17 minPro NETWORK-148A PBR next-hop tracks the firewall IP, but the firewall can still answer ARP while the service process behind it is deadThe tracked object remains reachable even though the real dependency has failed.NetworkAdvanced17 minPro NETWORK-330A route summary survives while every specific path behind it is now gone and traffic keeps choosing the black hole during a failover rehearsalAggregation stays healthy after the real forwarding options disappeared. Normal traffic masked the issue until the standby or alternate path became active under rehearsal conditions.NetworkIntermediate17 minPro NETWORK-221A route-map matches the right prefix set while one additive community action is replaced instead of appended after a maintenance template changeThe route is still policy-matched, yet a downstream signal disappears because one action semantics was misunderstood. The path looked healthy before the template changed, but one inherited assumption no longer matches the live environment.NetworkAdvanced17 minPro NETWORK-225A route-map matches the right prefix set while one additive community action is replaced instead of appended after a retention policy refreshThe route is still policy-matched, yet a downstream signal disappears because one action semantics was misunderstood. The operational object still exists somewhere in the system, but the lifecycle policy around its supporting state no longer matches reality.NetworkAdvanced17 minPro NETWORK-223A route-map matches the right prefix set while one additive community action is replaced instead of appended after an environment identity renameThe route is still policy-matched, yet a downstream signal disappears because one action semantics was misunderstood. The functional path still exists, but one identity, namespace, or naming assumption still points at the previous environment contract.NetworkAdvanced17 minPro NETWORK-141A route-policy preserves MED during normal operation, but a maintenance template strips it on the backup edge and inbound traffic never returns after failoverPaths exist both ways, yet partner preference signals vanish only on the standby path.NetworkAdvanced17 minPro NETWORK-119A route-policy regex matches the AS path set too broadly and blackholes partner prefixes that should stay externalTraffic loss starts after a policy cleanup because the new pattern captures more paths than the operator intended.NetworkAdvanced17 minPro