Cisco DCID 300-610 flashcards

34 cards. Read the term and the definition here. The deck at the top of this page is optional.

vPC peer-link

A PortChannel connecting two vPC peer switches that carries control-plane and data traffic, must include at least two links, and requires a separate peer-keepalive path over a routed network.

VXLAN MTU overhead

VXLAN adds 50 bytes of encapsulation (outer UDP/IPv4, VXLAN header, inner Ethernet frame); a 1500-byte payload requires underlay MTU of at least 1550, typically configured as 9216 jumbo frames.

BGP EVPN route types

Type 2 advertises MAC/IP bindings, Type 3 advertises inclusive multicast (VTEP discovery), and Type 5 advertises IP prefixes; these replace flood-and-learn for VXLAN overlay control.

Oversubscription ratio

The ratio of total downlink bandwidth to total uplink bandwidth at a switching tier; a 3:1 ratio means 3 Gbps of host-facing capacity for every 1 Gbps of uplink capacity.

ACI endpoint group

An EPG is a policy container grouping endpoints with common network requirements; communication between EPGs is controlled by contracts that specify provider and consumer relationships with filters.

Leaf-spine topology

A two-tier Clos design where every leaf connects to every spine; any leaf-to-leaf path is exactly one hop, providing predictable east-west latency and ECMP load balancing across spines.

vPC consistency check

A validation that type-1 parameters (STP mode, MTU, vPC domain ID, port-channel mode) match on both peers; mismatches suspend vPC member ports, while type-2 mismatches only trigger a warning.

UCS service profile

A logical server definition referencing server pools, BIOS and boot policies, vNIC/vHBA templates, and firmware policies; it enables stateless computing by abstracting configuration from physical blade hardware.

UCS fabric interconnect

The pair of switches that manage a UCS domain in active/active cluster mode with a single VIP; they connect to chassis IOMs and provide LAN/SAN uplinks to the data center network.

Cisco Intersight

A cloud-based management platform for UCS, Intersight Managed Mode replaces UCS Manager on supported platforms, offering policy-based configuration, firmware management, and hardware compatibility checks.

SAN boot policy

A UCS boot policy that defines the order of boot devices including FC or iSCSI LUNs; the LUN must be zoned correctly and mapped to a consistent LUN ID (usually LUN 0) for reliable boot.

Stateless computing

A design where server identity (UUID, MAC, WWPN) and configuration are stored in a service profile rather than on hardware, allowing a profile to be reassigned to a replacement blade without reconfiguration.

UCS firmware bundles

Infrastructure bundles update fabric interconnects, IOMs, and CIMCs; server bundles update BIOS, adapters, and storage controllers; firmware policies apply these at service-profile or domain level.

Dual-fabric SAN

A production Fibre Channel design with two independent fabrics (A and B); each host HBA connects to one fabric, ensuring a single fabric failure does not remove host access to storage.

Single-initiator zoning

A zoning best practice where each zone contains one host initiator WWN and one or more target WWNs; this limits fabric change notifications and reduces the blast radius of misconfigurations.

VSAN

A Virtual SAN partitions a physical Fibre Channel switch into independent fabric instances, each with its own domain ID, zoning database, and principal switch election; IVR routes traffic between VSANs.

NPIV

N_Port ID Virtualization allows a single physical N_Port to register multiple WWNs with the fabric, enabling virtual machines and NPIV-based applications to have independent fabric identities.

FCoE requirements

FCoE encapsulates FC frames in Ethernet (Ethertype 0x8906) and requires lossless Ethernet with PFC (802.1Qbb) and ETS (802.1Qaz); FIP (0x8914) handles discovery and login.

iSCSI CHAP

Challenge Handshake Authentication Protocol used by iSCSI targets and initiators; one-way authenticates the target to the host, mutual CHAP authenticates both directions for stronger security.

RPO and RTO

Recovery Point Objective is the acceptable amount of data loss measured in time; Recovery Time Objective is the acceptable downtime; synchronous replication targets near-zero RPO but requires low latency.

NPV mode

N_Port Virtualization makes an edge switch act as an NP_Port to the core, forwarding fabric traffic without consuming a domain ID; it requires NPIV support on the upstream switch.

HSRP virtual MAC

Cisco Hot Standby Router Protocol uses virtual MAC 0000.0c07.acXX where XX is the group number in hex; the active router responds to ARP for the virtual IP address.

VRRP

Virtual Router Redundancy Protocol is standards-based first-hop redundancy using virtual MAC 0000.5e00.01XX; it elects a master and backups based on priority, unlike HSRP's explicit active/standby.

ACI service graph

A policy object that defines how traffic is redirected through L4-L7 devices such as firewalls and load balancers using PBR; it specifies provider and consumer connectors and device cluster interfaces.

PIM Sparse Mode

A multicast routing mode using an explicit Rendezvous Point; receivers join via IGMP, and traffic flows only to interested receivers, making it suitable for VXLAN BUM traffic in underlay networks.

DHCP snooping

A Layer 2 security feature that filters untrusted DHCP messages and builds a binding table of legitimate client MAC-to-IP mappings, preventing rogue DHCP servers and IP spoofing attacks.

DCBX

Data Center Bridging Exchange negotiates QoS, PFC, and ETS parameters between DCB-capable peers; mismatches can cause FCoE or lossless traffic to fail across a link.

TACACS+ vs RADIUS

TACACS+ (TCP 49) encrypts the entire payload and separates authentication, authorization, and accounting; RADIUS (UDP 1812/1813) encrypts only the password and combines AAA in one exchange.

NX-API

A Cisco NX-OS REST API that exposes CLI commands and structured JSON output over HTTP/HTTPS; it supports CLI mode for show/exec commands and JSON-RPC mode for programmatic configuration.

APIC REST API

The Cisco ACI controller API using XML or JSON over HTTPS; authentication uses aaaLogin to obtain a token, and objects are addressed by distinguished names such as uni/tn-tenant/ap-app/epg-epg.

Ansible idempotency

A property where running the same playbook multiple times produces the same result without duplication; modules check current state and only apply changes when the desired state differs.

Streaming telemetry

A push-based monitoring model using gNMI/gRPC or NX-OS telemetry to send structured data at configured intervals, replacing SNMP polling and enabling near-real-time anomaly detection.

Terraform state file

A file that records the mapping between declared resources and real infrastructure; it enables Terraform to compute changes and detect drift, and it should be stored remotely with locking for team use.

ASHRAE inlet temperature

The recommended data center inlet air temperature range of 18-27 degrees Celsius (64.4-80.6 Fahrenheit); operating within this range balances equipment reliability and cooling energy efficiency.