Networking

Portal | Tag Cloud | 108 assets across 31 topics

TCP/IP, DNS, VLANs, routing, firewalls, load balancing, VPNs

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Core Skills (Tier 1)

Start here — these are the topics a mid-level engineer uses weekly.

• DNS — Topic Pack ×5, Exercise Set, Drill, Scenario, Runbook, Assessment, Case Study ×5
• TCP/IP — Topic Pack ×5, Drill, Scenario, Assessment, Case Study ×3
• VLANs — Topic Pack ×3, Scenario, Assessment, Case Study ×5
• Routing — Topic Pack ×2, Scenario, Assessment, Case Study ×6
• Linux Networking Tools — Topic Pack ×6, Drill, Scenario ×5, Case Study ×15
• Cisco CLI — Topic Pack ×2, Scenario
• TLS / Certificates (alias → tls_pki)
• Firewalls — Topic Pack ×2, Case Study ×2
• Load Balancing — Topic Pack ×3, Runbook
• Networking Troubleshooting Tools — Topic Pack
• DNS Deep Dive — Topic Pack
• DHCP & IP Address Management — Topic Pack
• HTTP Protocol — Topic Pack ×2
• Email Infrastructure — Topic Pack
• Linux Networking Tools (alias → linux_ops) — Topic Pack
• Subnetting & IP Addressing — Topic Pack
• Networking Troubleshooting — Topic Pack, Runbook ×4

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All Content

📘 Topic Packs

Asset	Topics	Level	Time	Status
API Gateways & Ingress	Load Balancing	L2	5h	solid
ARP	ARP	L1	2h	solid
AWS Networking	TCP/IP	L1	4h	solid
AWS Route 53	DNS	L2	3h	solid
BGP EVPN / VXLAN	BGP EVPN / VXLAN	L2	5h	solid
Cisco Fundamentals for DevOps	Cisco CLI, LACP / Link Aggregation, STP / Spanning Tree	L1	4h	solid
DHCP & IP Address Management	DHCP & IP Address Management, DNS, TCP/IP	L1	4h	solid
DNS Deep Dive	DNS, DNS Deep Dive	L1	4h	solid
DNS Operations	DNS	L2	4h	solid
DNSSEC & DNS Security	DNSSEC & DNS Security	L2	4h	solid
Email Infrastructure	Email Infrastructure	L1	3h	solid
Firewalls	Firewalls	L1	2h	solid
HAProxy & Nginx for Ops	Load Balancing	L2	4h	solid
HTTP Protocol	HTTP Protocol	L0	3h	solid
LACP	LACP / Link Aggregation	L1	2h	solid
Linux Ops	Linux Networking Tools (alias → linux_ops)	L0	5h	solid
MTU	MTU	L1	2h	solid
Mental Models (Core Concepts)	Linux Networking Tools	L0	4h	solid
NAT	NAT	L1	2h	solid
Network Automation	Network Automation	L2	5h	solid
Networking Deep Dive	Cisco CLI, DNS, LACP / Link Aggregation	L1	6h	solid
Networking Troubleshooting	Linux Networking Tools, Networking Troubleshooting, Networking Troubleshooting Tools	L1	5h	solid
Nginx & Web Servers	Load Balancing	L1	5h	solid
Routing	Routing	L1	2h	solid
STP (Spanning Tree)	STP / Spanning Tree	L1	2h	solid
Subnetting & IP Addressing	Subnetting & IP Addressing	L1	2h	solid
TCP/IP Deep Dive	TCP/IP, TCP/IP Deep Dive	L2	5h	solid
Tailscale & Zero Trust Networking	Tailscale & Zero Trust Networking, VPN & Tunneling	L2	3h	solid
VLANs	VLANs	L1	2h	solid
VPN & Tunneling	Firewalls, Linux Networking Tools, VPN & Tunneling	L2	5h	solid
Wireshark & Packet Analysis	Linux Networking Tools, Wireshark & Packet Analysis	L2	4h	solid
gRPC & Protocol Buffers	gRPC & Protocol Buffers, HTTP Protocol	L2	3h	solid
iptables & nftables	Linux Networking Tools	L1	4h	solid

🏋️ Exercise Sets

Asset	Topics	Level	Time	Status
Incident Simulator (18 scenarios) (CLI)	DNS	L2	4h	solid

⚡ Drills

Asset	Topics	Level	Time	Status
Networking Drills	DNS, Linux Networking Tools, TCP/IP	L1	30m	solid

🎯 Scenarios

Asset	Topics	Level	Time	Status
Adversarial Interview Gauntlet (30 sequences)	TCP/IP	L2	15h	solid
Scenario: Asymmetric Routing	Linux Networking Tools, Routing	L2	20m	solid
Scenario: DNS Looks Fine but App Fails	DNS	L2	20m	solid
Scenario: Duplex Mismatch	Linux Networking Tools	L1	20m	solid
Scenario: MTU Blackhole	Linux Networking Tools, MTU	L2	20m	solid
Scenario: NIC Flapping / LACP Mismatch	LACP / Link Aggregation, Linux Networking Tools	L2	20m	solid
Scenario: OOB Unreachable but Host Responds	Linux Networking Tools	L2	20m	solid
Scenario: VLAN Trunk Mismatch	Cisco CLI, VLANs	L2	20m	solid

📋 Runbooks

Asset	Topics	Level	Time	Status
Runbook: DNS Resolution Failure	DNS, Networking Troubleshooting	L1	15m	solid
Runbook: Load Balancer Health Check Failure	Load Balancing, Networking Troubleshooting	L2	15m	solid
Runbook: MTU Mismatch	MTU, Networking Troubleshooting	L2	15m	solid
Runbook: Network Partition (Split Brain / Partial Connectivity)	Networking Troubleshooting	L2	20m	solid

📝 Assessments

Asset	Topics	Level	Time	Status
Skillcheck: Networking Fundamentals	DNS, Routing, TCP/IP	L1	30m	solid

🔍 Case Studys

Asset	Topics	Level	Time	Status
Case Study: API Latency Spike — BGP Route Leak, Fix Is Network ACL	BGP EVPN / VXLAN, Linux Networking Tools	L2	30m	solid
Case Study: ARP Flux Duplicate IP	ARP, Linux Networking Tools	L2	30m	solid
Case Study: Asymmetric Routing One Direction	Routing	L2	30m	solid
Case Study: BGP Peer Flapping	Routing	L2	30m	solid
Case Study: Backup Job Failing — iSCSI Target Unreachable, VLAN Misconfigured	VLANs	L2	30m	solid
Case Study: Bonding Failover Not Working	LACP / Link Aggregation	L1	30m	solid
Case Study: CoreDNS Timeout Pod DNS	DNS	L2	30m	solid
Case Study: DHCP Relay Broken	Linux Networking Tools, VLANs	L1	30m	solid
Case Study: DNS Looks Broken — TLS Expired, Fix Is Cert-Manager	DNS	L2	30m	solid
Case Study: DNS Resolution Slow	DNS	L1	30m	solid
Case Study: DNS Split Horizon Confusion	DNS	L2	30m	solid
Case Study: Duplex Mismatch Symptoms	Linux Networking Tools, TCP/IP	L1	30m	solid
Case Study: Firewall Shadow Rule	Firewalls	L2	30m	solid
Case Study: IPTables Blocking Unexpected	Firewalls, Linux Networking Tools	L2	30m	solid
Case Study: Jumbo Frames Partial	Linux Networking Tools, MTU	L2	30m	solid
Case Study: LACP Mismatch One Link Hot	LACP / Link Aggregation	L2	30m	solid
Case Study: MTU Blackhole TLS Stalls	MTU	L2	30m	solid
Case Study: Multicast Not Crossing Router	Routing, VLANs	L2	30m	solid
Case Study: NAT Exhaustion Intermittent	TCP/IP	L2	30m	solid
Case Study: Network Loop Broadcast Storm	VLANs	L2	30m	solid
Case Study: OSPF Stuck In Exstart	Routing	L2	30m	solid
Case Study: Proxy ARP Causing Issues	ARP, Routing	L2	30m	solid
Case Study: SSH Timeout — MTU Mismatch, Fix Is Terraform Variable	MTU	L2	30m	solid
Case Study: Service Mesh 503s — Envoy Misconfigured, RBAC Policy	Linux Networking Tools	L2	30m	solid
Case Study: Source Routing Policy Miss	Linux Networking Tools, Routing	L2	30m	solid
Case Study: Stuck NFS Mount	Linux Networking Tools	L2	30m	solid
Case Study: TCP RST After Idle	TCP/IP	L2	30m	solid
Case Study: VLAN Trunk Mistag	VLANs	L1	30m	solid
Ops Archaeology: The 5% That Can't Resolve	DNS	L2	30m	solid
Ops Archaeology: The Certificate That Works Sometimes	Linux Networking Tools	L2	30m	solid
Ops Archaeology: The Cluster That Disagrees With Itself	Linux Networking Tools	L2	30m	solid
Ops Archaeology: The DR That Looks Ready But Isn't	Linux Networking Tools	L2	30m	solid
Ops Archaeology: The Gateway That Returns 502	Linux Networking Tools	L1	30m	solid
Ops Archaeology: The Replica That Fell Behind	Linux Networking Tools	L2	30m	solid
Ops Archaeology: The Requests That Vanish	Linux Networking Tools	L2	30m	solid