DCN LAB — 10 selected experiments | Exam preparation kit

Selected experiments: 1, 3.2, 6, 7, 8, 9, 10, 12, 13, 14. Basis: DCN LAB MANUAL 2025-26.pdf, pages 1–110. This is a study and permitted-practice pack, not a substitute for choosing the answer that matches the actual question.

Fast study order (limited time)

1. Read LAST_MINUTE_REVISION.md (one-line recognition of each question).
2. Read MASTER_CISCO.md for the reusable Cisco CLI skeleton and its topic-specific changes.
3. Read MASTER_PYTHON.md for reusable TCP/UDP socket logic and the different REST/XOR/RSA patterns.
4. For the actual question, open its Exp_*/README.md, execute its matching file, and compare with EXPECTED_OUTPUT.txt.

No single unchanged Cisco configuration or single Python script can correctly answer all ten questions. For example, VLAN segmentation, DHCP allocation and routing are different tasks; REST, sockets and cryptography require different logic. These masters reduce memorisation without replacing the question-specific steps.

Exactly two optional Python practice runners

These two real .py files are convenient shortcuts; they cover the selected Python experiments, but do not write both entire runners as your answer when an exam asks one specific program. Instead use the short matching program in its experiment folder.

• MASTER_NETWORK.py — TCP server/client, UDP server/client, short TCP delay demo, and REST GET. In two terminals, run python MASTER_NETWORK.py tcp-server first, then python MASTER_NETWORK.py tcp-client; replace tcp with udp, or use delay-server/delay-client. For REST run python MASTER_NETWORK.py rest (requires requests and internet).
• MASTER_SECURITY.py — run python MASTER_SECURITY.py xor or python MASTER_SECURITY.py rsa (requires cryptography for RSA).

Folder contents

Each experiment contains README.md (Aim → Steps → Commands/Program → Expected Output → Result → Viva), EXPECTED_OUTPUT.txt, plus runnable .py, Packet Tracer .cli, or command reference files as appropriate. The main index.html works offline and provides styled reading views. Sample outputs are illustrations, not claims that your Packet Tracer or network generated them.

Running Python on Windows: Open VS Code terminal in the experiment folder, type python filename.py. For socket client/server, open two terminals and start server first. Python dependencies are in requirements.txt.

Packet Tracer note: A .cli file is a text command reference, not a Packet Tracer .pkt project. Build the topology in Packet Tracer and enter commands at the appropriate device CLI. Check actual port labels with show ip interface brief / show cdp neighbors before applying configs. Never paste # explanations into device CLI.

Wireshark note: Capture only traffic on your own or an authorized network. Loopback sockets require capturing from the loopback interface; an Ethernet capture cannot automatically see Packet Tracer simulation traffic.

Two source clarifications: The manual labels the XOR program under an asymmetric heading on page 105; XOR with a shared key is a symmetric illustration. The manual's NAT example uses a serial link; this kit includes a complete Ethernet adaptation for Packet Tracer with a reachable simulated outside device. Wireshark and router output vary with environment.