Vendor560 problems· 4 reviewed

Cisco

560 incident problems in Cisco environments.

All problems (560)

NETWORK-1638A VRF route exists and one test still failsOne VRF test still fails after an SVI rename.NetworkBeginner7 minFree NETWORK-1658A VRF route exists and one test still failsOne VRF test still fails after an SVI rename.NetworkBeginner7 minFree NETWORK-1668A VRF route exists and one test still failsOne VRF test still fails after an SVI rename.NetworkBeginner7 minFree NETWORK-1614An OSPF adjacency stays downOne adjacency stays down after an OSPF area cleanup.NetworkBeginner7 minFree NETWORK-019After a BGP route change, only certain ASNs take a detour pathA network operations problem where the global route is alive but only certain carrier networks get an inefficient detour.NetworkAdvanced30 minPro NETWORK-1559A WAN failover drill succeeds and one branch still blackholes return trafficOne branch blackholes return traffic only after a failover drill.NetworkAdvanced12 minPro NETWORK-1397An MLAG pair carries normal traffic and a disaster-recovery test failsAn MLAG pair carries normal traffic and a disaster-recovery test fails focuses on cluster-maintenance and asks the reader to isolate the key signal in Cisco. Recovery paths can drift silently because they are invisible during steady-state operation.NetworkAdvanced15 minPro NETWORK-1387An MLAG pair looks stable and one VLAN blackholes east-west trafficAn MLAG pair looks stable and one VLAN blackholes east-west traffic focuses on incident-response and asks the reader to isolate the key signal in Cisco. Native VLAN drift hides until an untagged recovery path is the only path left.NetworkAdvanced15 minPro NETWORK-154A management VRF can reach the TACACS server, but the source interface changed after a chassis swap and the AAA server rejects the unknown client addressReachability exists, yet trust is anchored to a previous device identity.NetworkAdvanced16 minPro NETWORK-1287A BFD-assisted routing failover flaps repeatedlyFast failover becomes unstable after a QoS change even though throughput tests show the path is otherwise healthy.NetworkAdvanced17 minPro NETWORK-1271A BGP session stays Established but traffic preference changesA provider-facing BGP session remains healthy while traffic suddenly shifts to another path after an upstream policy change.NetworkAdvanced17 minPro NETWORK-1283A VRRP or HSRP pair appears healthy but east-west traffic breaksA first-hop redundancy event finishes and only some segments continue blackholing traffic toward the old gateway MAC.NetworkAdvanced17 minPro 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-1258An IS-IS adjacency never formsA backbone link carries traffic normally but IS-IS adjacencies never come up across it.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-1264A backup Layer 2 path wakes up during maintenance and spanning tree instantly blocks itNetwork incident scenario used for structured troubleshooting practice.NetworkAdvanced18 minPro NETWORK-1269A backup Layer 2 path wakes up during maintenance and spanning tree instantly blocks itA maintenance change activates a backup trunk that has not forwarded in months and an access segment immediately becomes unstable.NetworkAdvanced18 minPro NETWORK-1278A BGP keepalive path is stable but larger updates failA peering looks healthy until one change introduces larger update sets and route learning becomes inconsistent.NetworkAdvanced18 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