Networking for DevOps: Debug Connections Fast
Learn networking for DevOps: IP addresses, subnets, DNS, TCP, HTTPS, firewalls, load balancers and cloud VPCs, then debug real outages step by step.
What You'll Learn
Understanding Why Networking Matters in DevOps
It is 9:10 PM in Singapore. A team has just deployed a new orders service to an EC2 instance in ap-southeast-1.
Understanding Layers, TCP, UDP and Ports
Network communication is organised in layers so that each part can do one job and ignore the rest. You do not need to memorise every layer.
Working with IP Addresses, CIDR and Subnets
Every device on a network needs an address, and every cloud network you build starts with choosing address ranges.
Understanding Gateways, Routers and NAT
Packets need a way out of your local network, and private addresses need a way to reach the public internet.
Resolving Names with DNS
Humans remember names, and machines route by numbers.
Understanding HTTP, HTTPS and TLS
Most of the traffic you manage as a DevOps engineer is HTTP: APIs, health checks, load balancer rules and web servers.
Skills You'll Master
Curriculum Index12 topics
Understanding Why Networking Matters in DevOps
It is 9:10 PM in Singapore. A team has just deployed a new orders service to an EC2 instance in ap-southeast-1.
Understanding Layers, TCP, UDP and Ports
Network communication is organised in layers so that each part can do one job and ignore the rest.
Working with IP Addresses, CIDR and Subnets
Every device on a network needs an address, and every cloud network you build starts with choosing address ranges.
Understanding Gateways, Routers and NAT
Packets need a way out of your local network, and private addresses need a way to reach the public internet.
Resolving Names with DNS
Humans remember names, and machines route by numbers.
Understanding HTTP, HTTPS and TLS
Most of the traffic you manage as a DevOps engineer is HTTP: APIs, health checks, load balancer rules and web servers.
Controlling Access with Firewalls and SSH
A firewall decides which traffic may pass, and SSH is how you reach your servers.
Distributing Traffic with Load Balancers and Reverse Proxies
One server is a single point of failure and a hard ceiling on capacity.
Designing Cloud Networks with VPCs
A cloud network is the same ideas you have already learned, rebuilt as software settings.
Troubleshooting Connections Step by Step
You now have the vocabulary. This topic turns it into a calm routine you can follow at 2 AM, when guessing is most...
Practicing Networking in a Hands-On Lab
Reading builds the map and doing builds the instinct.
Reviewing Commands, Mistakes and Next Steps
This last topic gathers the commands you will actually use, the mistakes that cause most real incidents, and a short...
Career Impact
Roles that use the skills in this module.
- High Demand
DevOps Engineer
₹8L - ₹18L a year
- Very High
Cloud Engineer
₹6L - ₹14L a year
- Critical / Niche
Site Reliability Engineer (SRE)
₹10L - ₹24L a year
Next Modules
Related Guides
Practice on the Coding Sheet
Not a software engineer sheet. Every problem comes from real DevOps, SRE, Platform and Cloud interviews, from your first script to a system you build yourself.
Open the Coding SheetFrequently Asked Questions
No. You need to understand how addresses, names, ports and firewalls work well enough to find where a connection breaks. That is what this module teaches. Deep topics like routing protocols can wait until a job asks for them.
TCP sets up a connection and retransmits lost data, so applications receive bytes reliably and in order. UDP just sends independent messages with very little overhead and leaves loss handling to the application. Web pages, SSH and databases use TCP. DNS lookups usually use UDP.
Refused usually means the machine answered but nothing is listening on that port, or a rule actively rejected you. Timed out usually means packets were dropped silently, often by a firewall, security group or missing route. The difference tells you where to look first.
A subnet is public when its route table has a route to an Internet Gateway. A private subnet has no such route, so unsolicited internet traffic cannot reach it. Private resources can still reach out through a NAT gateway.