Designing Cisco Enterprise Networks (300-420 ENSLD)

What you will practice:

• IPv4 addressing plan structure
• Hierarchical addressing models (core/distribution/access, site/region-based summarization intent)
• VLSM p…

• IPv4 addressing plan structure
• Hierarchical addressing models (core/distribution/access, site/region-based summarization intent)
• VLSM planning for variable site sizes
• Address block allocation for growth (spare capacity strategy)
• Summarization boundaries and where summaries should exist (distribution/core/edge)
• IPv6 addressing plan structure
• Prefix allocation strategy (site prefixes, per-VLAN/per-segment planning)
• Aggregation goals (route summarization and stability)
• Addressing for services and infrastructure (loopbacks, P2P links, management networks)
• Operational design constraints
• Multitenancy/segmentation needs (how addressing aligns with VRFs and segmentation)

Tip: After topic practice, do mixed sets under time pressure and review missed questions immediately.

What you will practice:

• IGP selection criteria
• Convergence expectations, operational complexity, and scaling approach
• Scalability and stability design

• IGP selection criteria
• Convergence expectations, operational complexity, and scaling approach
• Scalability and stability design
• Failure domain control and topology choices
• Summarization design (where and why)
• Route filtering rationale (preventing churn and limiting propagation)
• Security design considerations
• Securing routing adjacencies (design intent: prevent spoofed neighbors/updates)
• Resiliency features
• Fast convergence philosophy and its tradeoffs (CPU/traffic stability)

Tip: After topic practice, do mixed sets under time pressure and review missed questions immediately.

What you will practice:

• BGP address families
• IPv4/IPv6 address families and the design implication of multi-AF deployments
• Basic route filtering

• BGP address families
• IPv4/IPv6 address families and the design implication of multi-AF deployments
• Basic route filtering
• Inbound/outbound filtering intent (control what you accept and what you advertise)
• Attributes for path preference
• Designing deterministic path selection using attributes (enterprise policy routing at scale)
• Route reflectors
• iBGP scaling patterns and where route reflectors fit in a large enterprise
• Load sharing
• Multi-path design intent (utilization and resiliency) and where it is appropriate

Tip: After topic practice, do mixed sets under time pressure and review missed questions immediately.

What you will practice:

• Overlay (tunneling) strategies
• When tunneling is used (constraints, islands, incremental rollout)
• Native dual-stack strategies

• Overlay (tunneling) strategies
• When tunneling is used (constraints, islands, incremental rollout)
• Native dual-stack strategies
• Running IPv4 and IPv6 in parallel (design drivers: app readiness, operational simplicity)
• Boundaries: IPv4/IPv6 translations
• Where translation functions typically live (edge/border) and why boundaries matter

Tip: After topic practice, do mixed sets under time pressure and review missed questions immediately.

What you will practice:

• First Hop Redundancy Protocols (FHRP)
• Default gateway resiliency design (active/standby concepts, failure detection implications)
• Platf…

• First Hop Redundancy Protocols (FHRP)
• Default gateway resiliency design (active/standby concepts, failure detection implications)
• Platform abstraction techniques
• Designing to reduce dependency on specific hardware behaviors (operational consistency goal)
• Graceful restart
• Maintaining forwarding during control-plane restarts (impact on uptime)
• BFD
• Fast failure detection as a design component (ties directly to convergence objectives)

Tip: After topic practice, do mixed sets under time pressure and review missed questions immediately.

What you will practice:

• STP scalability
• Design choices that limit STP complexity and reduce instability
• Fast convergence

• STP scalability
• Design choices that limit STP complexity and reduce instability
• Fast convergence
• L2 design that minimizes reconvergence time during failures/changes
• Loop-free technologies
• Designing to prevent bridging loops (and the symptoms loops create)
• PoE and Wake-on-LAN
• Power delivery as part of campus design (phones/APs/IoT endpoints)
• Layer 2 security techniques (STP security, port security, VACL)
• Preventing rogue switches/loops
• Preventing unauthorized endpoint access
• Using VLAN ACLs for segmentation enforcement at Layer 2

Tip: After topic practice, do mixed sets under time pressure and review missed questions immediately.

What you will practice:

• Convergence design
• Failure domain shaping; convergence vs stability trade-offs
• Load sharing

• Convergence design
• Failure domain shaping; convergence vs stability trade-offs
• Load sharing
• Designing for ECMP/traffic distribution where appropriate
• Route summarization
• Summaries as a stability tool (reducing table size and churn)
• Route filtering
• Controlling propagation between domains/regions/sites
• VRFs
• Segmentation via multiple routing tables (multi-tenant and separation requirements)
• Optimal topologies
• Campus/core interconnect design choices that minimize bottlenecks and reduce blast radius
• Redistribution
• Designing redistribution safely (avoiding loops, controlling route leakage, policy intent)

Tip: After topic practice, do mixed sets under time pressure and review missed questions immediately.

What you will practice:

• SD-Access architecture
• Underlay vs overlay
• Control plane vs data plane

• SD-Access architecture
• Underlay vs overlay
• Control plane vs data plane
• Automation principles
• Wireless integration concepts
• Security components at a design level
• Fabric design considerations for wired and wireless access
• Overlay and fabric design choices
• Control-plane design considerations
• Border design considerations
• Segmentation and virtual networks
• Scalability considerations
• Wireless over-the-top vs fabric for wireless
• Multicast considerations inside the fabric

Tip: After topic practice, do mixed sets under time pressure and review missed questions immediately.

What you will practice:

• WAN connectivity options for on-prem, hybrid, and cloud
• Layer 2 VPN
• MPLS Layer 3 VPN

• WAN connectivity options for on-prem, hybrid, and cloud
• Layer 2 VPN
• MPLS Layer 3 VPN
• Metro Ethernet
• DWDM
• 4G/5G
• SD-WAN customer edge
• Site-to-site VPN design
• DMVPN
• IPsec
• GRE
• GET VPN
• WAN high availability design
• Single-homed vs multihomed
• Backup connectivity
• Failover design
• Cisco SD-WAN architecture (orchestration, management, control, data planes)
• Onboarding and provisioning
• Security components
• Cisco SD-WAN design considerations (overlay/control design, LAN integration, HA, scalability, QoS, multicast)

Tip: After topic practice, do mixed sets under time pressure and review missed questions immediately.

What you will practice:

• Network Services: QoS strategy selection (DiffServ vs IntServ)
• End-to-end QoS policy design (classification/marking, shaping, policing, q…

• Network Services: QoS strategy selection (DiffServ vs IntServ)
• End-to-end QoS policy design (classification/marking, shaping, policing, queuing)
• Network management technique design (in-band vs out-of-band, segmented management networks, prioritizing management traffic)
• Multicast concepts and services design (RPF, rendezvous points, SSM, PIM bidirectional, MSDP)
• Automation: YANG model ecosystems (IETF vs OpenConfig vs Cisco)
• NETCONF vs RESTCONF
• Model-driven telemetry (periodic vs on-change publication)
• gRPC and gNMI
• Cloud connectivity options (direct connect, cloud on ramp, MPLS direct connect, WAN integration)
• Cloud service models (SaaS, PaaS, IaaS)

Tip: After topic practice, do mixed sets under time pressure and review missed questions immediately.