CO
DOCUMENT

Computer Networking Foundations: OSI, TCP/IP, Routing and Common Ports

A Chinese-language PDF guide for layered models, addressing, routing, transport protocols, ports and evidence-led connectivity troubleshooting.

Version 2026-08-22通用Public reference material; verify the included notice and original terms before redistribution

What this networking PDF covers

This Chinese-language PDF uses a layered path—models, addressing, transport, services and troubleshooting—to explain why a connection succeeds or fails. It links DNS, transport state, routing, listening ports and application responses into one traceable scenario.

The English page is a searchable summary and file guide. A port table is an initial clue, not proof of a service; protocol, listener, direction, time and policy must be checked together.

A connection-trace workflow

Define source, destination, protocol, time and expected result. Follow name resolution, route selection, handshake, listener and application response, recording one piece of evidence per stage.

File and scope note

The indexed file is a 109.93 KB PDF. Use isolated or explicitly scoped networks for experiments, and record the version date with the troubleshooting notes. Content review date: 2026-08-23.

SAVE TO CLOUD

Save to your cloud drive

Save the complete collection first so files remain together and are easier to access across devices.

Links checked 2026-08-06
Save first, access when you need itOn desktop, scan with the matching cloud-drive app. On mobile, tap the save button.
GUIDE

Computer networking foundations study guide

Trace one connection from name resolution to application response while using the OSI and TCP/IP layers to classify evidence.

Before you start

  • Know binary numbers, IP addresses, domains and basic command-line operations.
  • Have a PDF reader and an isolated network lab.
  • Prepare a table for source, destination, protocol, port, state and time.
02

Quick start

  1. 01

    Mark the layers

    List application, transport, network and link layers and assign a likely layer to each symptom.

  2. 02

    Trace one connection

    Record name resolution, address, protocol, port and state changes from the first lookup to the transport setup.

  3. 03

    Test route selection

    Use fictional networks to compare direct delivery, default routes and next hops, and write where each packet goes.

  4. 04

    Locate the fault

    Split failure into resolution, reachability, handshake, listening port and application response, validating one stage at a time.

Usage tips

  • Treat port numbers as clues and confirm service identity, listener state, direction and policy.
  • Retain timestamps, addresses and command output instead of relying only on a browser symptom.
  • Start with the smallest test scope and confirm the environment boundary before expanding packet inspection.
Troubleshooting and uninstall

The domain resolves but the service does not open. What sequence helps?

Check resolved address, route reachability, transport handshake, target listener and application response separately.

How can I avoid confusing the next hop in a routing question?

Write the destination network and local route table, apply longest-prefix matching, and then name the interface or next hop.

FAQ

Frequently asked questions

How should OSI and TCP/IP be studied together?

Use OSI to label the problem layer and TCP/IP to connect that layer to the protocols in a real connection path.

What can a common-port table tell me?

It gives an initial clue; service, listener, direction and firewall or policy state still need verification.

What format and size is the file?

The indexed resource is a 109.93 KB PDF; verify the filename and size after downloading.