Subnetting Cheat Sheet (IPv4)
Quick reference for CIDR, subnet masks, usable hosts, wildcard masks, and the “magic number” block size.
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Welcome & Rules
house rules, code formatting tips, how to ask great questions
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2
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2
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09-14-2025
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1
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09-13-2025
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Networking 101
For fundamentals: OSI model, IP addressing, subnets, routing vs. switching, ports, VLANs.
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2
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2
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09-14-2025
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Troubleshooting Clinic
Real problems, real fixes. Members post symptoms, environment, what they tried.
Pinned: “Question Template” (see template below) + a “Mark as Solved” guide
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Labs & Simulators
Hands-on practice with: Packet Tracer, GNS3, EVE-NG, Boson NetSim, eve-ng community images.
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Tools: Wireshark, Nmap & Friends
Packet captures, filters, scans, traces, tcpdump, iperf.
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Network Security (Blue-Team Basics)
Firewalls, ACLs, IDS/IPS, VPN, zero trust basics, common vulns, best practices.
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Home Lab & Hardware
SOHO routers, PoE switches, used enterprise gear, patch panels, racks, cabling, UPS.
Pinned: “Budget Home Lab Builds (2025 Edition)”
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Linux & Windows Networking
NIC config, routes, firewall (iptables/nftables, Windows Firewall), DNS, DHCP, SMB/NFS, AD basics.
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Cert Study Zone
Study plans, flashcards, practice labs, exam debriefs.
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Announcements & Site Feedback
Site updates, requests, bug reports, feature ideas.
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2
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09-14-2025
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09-14-2025, 04:31 PM -
Email is disabled for now — here’s what that means
Our hosting provider does not allow outbound email from this server. To keep things simple...09-14-2025, 11:52 AM -
Thread Prefixes — What they are, why they help, and how to use them
Prefixes are short labels (like [Help], [Solved], [HowTo]) that appear...09-14-2025, 01:28 AM