May 20, 2024
A Cautionary Tale: Don't Get Burnt by Your Firewall
A practical cautionary tale about firewall misconfiguration — and how a “secure” setup can quietly break production.
Read originalFirewalls cut both ways
Firewalls protect systems — until a rule is wrong, too broad, or silently blocks the traffic your app needs.
Lessons
- Document every production firewall change
- Test from outside the VPC, not only from bastion hosts
- Prefer explicit allowlists over tribal knowledge
Originally published on Medium.