Basics of Networks
7 questions
What is an IP address?
•A unique device identifier in the network.
•IPv4: 32 bits, format 192.168.1.1.
•IPv6: 128 bits, format 2001:0db8::
1.
•Public IP is visible on the internet.
•Private IP is within a local network.
How do TCP and UDP differ?
•TCP — reliable, with delivery acknowledgment.
•UDP — fast, without guarantees.
•TCP: HTTP, email, files.
•UDP: streaming, gaming, VoIP.
•TCP is slower due to handshake.
What are ports?
•Numeric identifier of a service (0-65535).
•80 HTTP, 443 HTTPS, 22 SSH.
•3306 MySQL, 5432 PostgreSQL.
•0-1023 — system ports.
•One IP can have many services on different ports.
Networking Basics: what is DHCP and how does it work?
On the topic "Networking Basics," start with requirements: what should work, what are the budget/performance/security constraints. Then choose a solution.
Networking Basics: how to diagnose network problems (ping, traceroute, nslookup)?
Practice for "Networking Basics": create a checklist (installation, configuration, backup, updates) and go through it once — this reduces the number of "mystical" problems.
Networking Basics: what is routing and default gateway?
Answer on "Networking Basics": updates and backups are more important than fine-tuning. Automate backups and enable 2FA.
Networking Basics: how to understand speed/loss/delay and where to look for bottlenecks?
For "Networking Basics," it is useful to: find the primary source (documentation, release notes) and reproduce the problem with a minimal example.