What you'll practice

100+ lab templates across four topic areas, spanning Beginner through Advanced. The material covers the same routing, switching, security, and services fundamentals tested on exams like CCNA and CompTIA Network+ - randomized differently every time you launch one, so you're practicing the skill, not memorizing an answer key.

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Routing

The largest slice of the catalog - from a first static route to multi-area OSPF.

Static & default routing

next-hop selection, default routes, routing table reads

OSPF

single- and multi-area, ABR behavior, adjacency & neighbor-state troubleshooting

EIGRP

variance, hub-and-spoke topologies

BGP

eBGP peering

Route summarization

IPv4 addressing & subnetting

CIDR, subnet- vs host-wide fault isolation

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Switching

VLANs, trunking, and the spanning-tree behavior that keeps a topology loop-free.

VLANs & trunking

switch-to-switch trunks, allowed-VLAN lists

Spanning Tree

root bridge election, per-VLAN vs whole-link failure

Router-on-a-stick & SVIs

inter-VLAN routing

Path troubleshooting

working-but-suboptimal paths

Security

Filtering traffic correctly - not just blocking it, but scoping and verifying the rule.

Access Control Lists (ACLs)

rule scope, default-deny

Stateful firewalls

iptables, nftables, connection tracking

Packet filtering

verifying behavior in all four directions

Network segmentation

Services

The infrastructure services every network leans on: addressing, resolution, translation.

DHCP

scopes, exclusions, pools

DNS

name resolution, round-robin, split-horizon, multi-address records

NAT & PAT

overload, port forwarding, inbound vs outbound translation

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CCNA is a registered trademark of Cisco Systems, Inc. CompTIA Network+ is a registered trademark of CompTIA, Inc. Subnetica is an independent practice platform and is not affiliated with, endorsed by, or sponsored by Cisco Systems, Inc. or CompTIA, Inc.