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BeginnerModule 7Lesson 2/5

Network Isolation Named

Network isolation literacy — VLAN segment, firewall deny, EDR network contain category — document isolating YOUR $HUNT_LAB host in notes.

15 min+40 XP3 quiz
Module progress2 of 5

Visual · t30_network_isolation_named

Network isolation = named segment/contain rows. $HUNT_LAB host notes. Original Cyberlium.

Opening

Network isolation stops spread — name VLAN, firewall, and EDR contain vocabulary on YOUR lab host notes, not stranger network attack paths.

Network isolation literacy names: VLAN or subnet segmentation category, host firewall deny-outbound stub, NAC port disable category, EDR 'network contain' feature category, and DNS sinkhole category at literacy level. Analyst writes isolation plan for $HUNT_LAB labeled host (e.g., hunt-lab-vm-07) — documents intended effect (no outbound except jump box category), rollback note, UTC — without executing isolation on prod, without scanning or pivoting stranger networks, without disabling employer firewall for 'practice.' Cyberlium: isolate YOUR lab host in written runbook row — defender decision literacy only. Refused: unauthorized prod network changes, lateral movement to test isolation, MITM on live traffic. Lab row: isolation plan template (method, scope, rollback, UTC) filled for one lab host.

1. Isolation methods named

VLAN segment, firewall deny, NAC disable, EDR network contain, DNS sinkhole — five literacy anchors.

Method choice depends on asset criticality and available tooling — lab stub documents tradeoff.

Command guide

Try these commands — Isolation methods named

═══ TOOLS & WEBSITES ═══ Browse / read these (authorized learning only — stay in YOUR lab / program scope)

Network isolation — https://csrc.nist.gov/publications/detail/sp/800-61/rev-2/final MITRE T1071 — https://attack.mitre.org/techniques/T1071/ (C2 containment context) FIRST — https://www.first.org/

═══ INSTALL ═══

Linux (Debian/Ubuntu):

Command — copy this

sudo apt install python3

macOS:

Command — copy this

brew install python3

Windows: Download https://python.org/downloads/

═══ LINUX / macOS ═══

Command — copy this

export HUNT_LAB=${HUNT_LAB:-$HOME/cyberlium-lab/t30-hunt}
cat > "$HUNT_LAB/ir/containment-decision-tree.md" <<'EOF'
# Containment Decision Tree — LAB scenario IDs ONLY
## LAB-IR-001 (jsmith / WIN-HUNT01 / 203.0.113.99)
```
Confirmed C2 beacon (HNT-003)?
  YES → Block 203.0.113.99 at perimeter (document rule)
       → Isolate WIN-HUNT01 to quarantine VLAN (YOUR lab VM)
       → Disable jsmith account (lab AD or doc)
  NO  → Continue monitoring, refine hunt hypothesis
## LAB-IR-002 (svc_backup / SMB lateral)
Confirmed unauthorized SMB (HNT-004)?
  YES → Disable svc_backup (lab doc)
       → Block 10.0.3.50→10.0.3.10:445 if unauthorized
  NO  → Verify change ticket, may be FP
```
NEVER: isolate stranger machines; NEVER: Impacket/Mimikatz/Cobalt recipes
All actions documented in markdown for YOUR lab VMs only
EOF

Command — copy this

grep -E 'LAB-IR|NEVER|203.0.113' "$HUNT_LAB/ir/containment-decision-tree.md"

Primary tools to practice this lesson: grep, python3. Reference sites: Network isolation (https://csrc.nist.gov/publications/detail/sp/800-61/rev-2/final); MITRE T1071 (https://attack.mitre.org/techniques/T1071/); FIRST (https://www.first.org/). Run every command in the box — install first, then the usage lines — only on YOUR lab / program scope.

2. Lab host note discipline

Write isolation plan for YOUR $HUNT_LAB host — label fictional hostname clearly.

Include rollback step — containment is not permanent by default.

3. Refused

No prod network isolation without RoE; no lateral movement to validate controls.

Isolation literacy supports defender response — not unauthorized network ops.

4. What you ship: network isolation plan row

Isolation method + lab host scope + rollback UTC + NEVER prod isolation without RoE line.

5. What you record before the next lesson

Network isolation plan row path.

6. Wrong vs right: stranger prod vs YOUR hunt telemetry

Worked failure — same MSF word, opposite target. Right never needs a café Wi-Fi or classmate laptop.

  • Wrong

    Isolate random employer workstation without ticket as 'EDR practice.'

  • Right

    Network isolation plan for $HUNT_LAB labeled host. Next: Account/Host Actions.

Mission: network isolation plan row

1) Name three isolation methods. 2) Fill plan template for one lab host. 3) Write rollback step UTC. 4) Write NEVER unauthorized prod isolation line.

Stuck? Ask Cyberlium AI Mentor

Ask Mentor: “EDR network contain — literacy vs full NAC?”

Knowledge Check

1

APPLY: Network isolation literacy uses:

Multiple choice

Knowledge Check

2

APPLY: True or False: Prod isolation without RoE is lab.

True or False

Knowledge Check

3

APPLY: Isolation plan should include:

Multiple choice

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Answer all 3 knowledge checks to continue. (0/3 answered)