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Cisco DCIT 300-615 study materials
Cisco DCIT 300-615 study resources

Cisco DCIT 300-615 cheat sheet

Cisco DCIT 300-615 · Keep the key ideas within reach.

Quick reference

Troubleshooting Cisco Data Center Infrastructure

  • Troubleshooting flow for DCIT scope: isolate the layer (physical, fabric/control plane, forwarding/data plane, policy/tenant), then verify with show commands before changing config; capture a baseline and diff after each change.

  • NX-OS logging: 'show logging logfile' shows syslog buffer; 'show logging server' shows remote syslog config; severity levels 0-7 with 0=emergencies; 'logging level ' filters per facility.

  • Interface faults: 'show interface' counters - CRC/input errors point to cabling/SFP; 'show interface counters errors' for FCS, runts, giants; 'show interface transceiver details' for DOM optical levels; 'show hardware internal' for ASIC-level drops.

  • vPC troubleshooting: verify 'show vpc' peer status, 'show vpc consistency-parameters global/interface' for type-1 (mandatory) mismatches; type-1 mismatch keeps vPC down, type-2 mismatch only warns. 'show vpc role' and 'show vpc peer-keepalive' confirm peer link and keepalive health.

  • Fabric path/STP: 'show spanning-tree vlan X' for root and port roles; 'show fabricpath isis adjacency' and 'show fabricpath route' for FP; 'show lldp neighbors' to map topology; 'show cdp neighbors detail' for management IPs.

  • Port-channel: 'show port-channel summary' shows member state (P/bundled, s/suspended, I/individual); 'show lacp neighbor' and 'show port-channel compatibility-parameters' for member mismatch; suspended members usually mean speed/duplex/MTU or vPC mismatch.

  • Tenant/VRF/EVPN: 'show vrf', 'show ip route vrf ', 'show bgp l2vpn evpn', 'show nve peers' and 'show nve vni' to confirm VXLAN tunnel and VNI state; 'show l2route evpn mac all' for MAC learning; 'show bgp l2vpn evpn route-type ' for type-2/type-5 routes.

  • Hardware and environment: 'show module', 'show environment', 'show inventory', 'show system resources', 'show processes cpu sort | head' and 'show processes memory sort | head' to find control-plane stress; 'show tech-support' collects full diagnostics for TAC.

  • Config and state compare: 'show running-config diff' after changes, 'show startup-config' vs running, 'show archive config differences' when checkpoint/rollback enabled; 'show configuration session' for staged changes before commit.