0x40Lesson 5 of 8

Connect VMs with virtual networking

Explore virtual switches, NAT, bridge modes, and security groups.

15 min 5-question quiz 1 code exercise

By the end of this lesson you can

Choose network modes for VM connectivity and exposure.

VMs connect through virtual NICs to virtual switches. In bridge mode, a VM appears directly on the local network. In NAT mode, VMs use private addresses and share host egress. Security groups or firewall rules control inbound and outbound traffic per VM or subnet.

vm_demo.py

1rules = [
2  {"port": 22, "action": "allow"},
3  {"port": 80, "action": "allow"},
4  {"port": 3306, "action": "deny"}
5]
6open_ports = [str(rule["port"]) for rule in rules if rule["action"] == "allow"]
7print(",".join(open_ports))

Output

22,80

Good VM networking design applies least privilege: open only required ports, segment workloads by function, and monitor east-west traffic. For public services, pair network policy with host hardening and patch discipline.

Key takeaways

Choose network modes for VM connectivity and exposure.
VMs are powerful when automation and guardrails stay strong.
Observe before scaling; recover before incidents become outages.

Lesson quiz

5 questions · pass with 4 correct · up to 50 XP

Passing this quiz completes the lesson and keeps your streak going. Questions you miss come back in review sessions later.

Practice: write Python

Write Python in the editor and run it against sample inputs. Python runs locally in your browser using a WebAssembly runtime.

Exercise 1

Evaluate a simple firewall rule

+25 XP

Read an integer port. Allow only 22, 80, or 443. Print allow for those ports; otherwise print deny.

https
database

main.py

Loading editor…

Python runs in a sandboxed browser worker with a 60 second time limit. Its runtime loads from the Pyodide CDN; your code stays in this browser.

Questions about this lesson

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