Vendor560 problems· 4 reviewed

Cisco

560 incident problems in Cisco environments.

All problems (560)

NETWORK-125Policy-based routing on the SVI forces user traffic toward a firewall but also bypasses the local DHCP relay pathSecurity steering works, but address assignment becomes unstable because a local service path was not exempted from the policy.NetworkIntermediate15 minPro NETWORK-1372Two OSPF neighbors stay in EXSTART after a VLAN migrationA routed VLAN migration completes and later one OSPF adjacency never progresses beyond EXSTART despite matching interface configs at the subinterface layer.NetworkAdvanced15 minPro NETWORK-139A CAPWAP access point reaches the controller, but DTLS setup failsLayer-3 reachability is fine, yet management onboarding stalls on the trust layer.NetworkIntermediate16 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-1310A route reflector shows every prefix and one client still blackholesA route policy cleanup on a reflector changes data-plane reachability without dropping any BGP session.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-1284A trunk carries the expected VLANs but one voice VLAN still failsPhones that worked on the old switch fleet stop joining the expected voice VLAN after a mixed-vendor refresh.NetworkIntermediate16 minPro NETWORK-1260A trunk comes up electrically but spanning tree blocks it with inconsistent port typeA new switch trunk is introduced and immediately lands in blocking with RECV_1Q_NON_TRUNK or similar inconsistency messages.NetworkIntermediate16 minPro NETWORK-1330An anycast gateway migration keeps the VLAN online and still creates...An anycast gateway migration keeps the VLAN online and still creates... focuses on incident-response and asks the reader to isolate the key signal in Cisco. Fabric convergence is often multi-stage and each table can believe...NetworkAdvanced16 minPro NETWORK-1337An Arista or EVPN leaf pair keeps flooding one segmentA mobility-heavy workload is migrated and later one segment shows flooding and intermittent loss even though the MAC has settled.NetworkAdvanced16 minPro NETWORK-1317An EVPN gateway migration preserves VLANs and still blackholes one segmentA fabric migration introduces an anycast gateway change and only one segment experiences intermittent blackholes afterward.NetworkAdvanced16 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-159NAT translations survive failover, but route-map based NAT exemption references an old object group and VPN traffic gets translated unexpectedlyConnectivity still exists, yet one policy layer stopped recognizing protected traffic after an object rename.NetworkIntermediate16 minPro NETWORK-1217Port appears healthy but PoE-powered phones still flapA voice access migration keeps one phone segment unstable even though interfaces show up and forwarding correctly.NetworkIntermediate16 minPro NETWORK-1256Two OSPF neighbors stay in ExStart or ExchangeA routing change enables OSPF between devices that can ping each other but never complete adjacency formation.NetworkIntermediate16 minPro NETWORK-1276A backup trunk wakes up during maintenance and causes root-inconsistent blockingA redundancy test activates a little-used link and suddenly one segment is blocked or err-disabled by spanning-tree policy.NetworkAdvanced17 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-1291A BGP session stays up but the preferred path disappearsA routing optimization on a reflector leads one downstream edge to change behavior without any session flap.NetworkAdvanced17 minPro NETWORK-160A campus fabric migration preserves the SVI gateway addresses, but one downstream ACL still keys off the old chassis MAC and security monitoring floods with false anomaliesRouting is fine, yet dependent controls still expect the previous gateway identity.NetworkAdvanced17 minPro