什么是 QUIC 协议？为什么 HTTP/3 用它？
What is the QUIC protocol, and why does HTTP/3 use it?
QUIC 基于 UDP 重建可靠传输，并把 TLS 握手与连接建立合并，减少往返次数；还能在切换网络时不断线，是 HTTP/3 的底层。
QUIC runs reliable transport over UDP and merges the TLS handshake with connection setup to cut round trips; it also survives network changes, the base of HTTP/3.
难度 专业 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-11-05
来源 · Source
互联网工程任务组（IETF）,《QUIC: A UDP-Based Multiplexed and Secure Transport》,RFC 9000,2021 (DOI: 10.17487/rfc9000)
IETF, 'QUIC: A UDP-Based Multiplexed and Secure Transport', RFC 9000, 2021, DOI: 10.17487/rfc9000
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.17487/rfc9000; RFC 9000
#QUIC #HTTP3
什么是 Anycast？它和 CDN 有什么关系？
What is Anycast, and how is it related to CDNs?
Anycast 让同一个 IP 地址公布在多个地点的服务器上，网络会把你引到最近的那台，常用于 DNS 根服务器和 CDN 边缘节点。
Anycast advertises the same IP from servers in many places, and routing sends you to the nearest one, used by DNS roots and CDN edges.
难度 专业 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#Anycast #路由
什么是 MTU 和 IP 分包（Fragmentation）？
What are MTU and IP fragmentation?
MTU 是网络层一次能传的最大包大小。若数据超出路径上某段 MTU，路由器可把包拆小，到目的地再重组。
MTU is the largest packet a link layer can carry. If data exceeds a hop's MTU, routers can split packets and reassemble them at the destination.
难度 专业 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#MTU #分包
除了 TCP 握手，TLS 握手又是在做什么？
Beyond the TCP handshake, what does the TLS handshake do?
TLS 握手在 TCP 之上协商加密套件、验证服务器证书、用密钥交换生成共享密钥，之后通信内容才被加密，保证私密与防篡改。
On top of TCP, the TLS handshake negotiates ciphers, verifies the server certificate, and uses key exchange to make a shared secret; only then is traffic encrypted.
难度 专业 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#TLS #HTTPS
HTTP/2 的多路复用（Multiplexing）解决了什么问题？
What problem does HTTP/2 multiplexing solve?
HTTP/1.1 同域名要排队建多个连接，队头阻塞会拖慢页面。HTTP/2 在一条连接上并行传多个请求，减少等待、提升加载速度。
HTTP/1.1 queued requests across several connections, and head-of-line blocking slowed pages. HTTP/2 sends many requests in parallel over one connection, cutting waits.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#HTTP2 #多路复用
为什么 TCP 断开连接需要四次挥手？
Why does closing a TCP connection need four waves?
TCP 是全双工，关闭时双方要各自说一声我发完了。服务器收到 FIN 后先回 ACK，等自己数据发完再发 FIN，因此多一次往返。
TCP is full-duplex, so each side must say it is done. The server ACKs your FIN, then sends its own FIN after finishing, adding an extra round trip.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#TCP #断开
什么是 HTTP 缓存（Cache-Control、ETag）？
What is HTTP caching (Cache-Control, ETag)?
服务器用 Cache-Control 告诉浏览器能缓存多久，用 ETag 给资源一个版本标识。再请求时浏览器可凭 ETag 问没变吧，没变就免传整份。
Servers use Cache-Control to say how long to cache, and ETag to tag a version. On later requests the browser can ask if unchanged, and skip re-downloading if so.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#HTTP #缓存
什么是负载均衡（Load Balancer）？
What is a load balancer?
负载均衡器把大量请求分摊到多台服务器上，避免单机过载，同时某台宕机时还能把流量转到健康机器，提升可用性。
A load balancer spreads many requests across servers to avoid overloading one, and reroutes traffic when a machine fails, improving availability.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#负载均衡 #架构
什么是反向代理（Reverse Proxy）？
What is a reverse proxy?
反向代理站在服务器前面，替后端接收请求并转发，可做负载均衡、缓存、HTTPS 卸载和隐藏真实服务器，是网站常见入口。
A reverse proxy sits in front of servers, receiving and forwarding requests; it can load-balance, cache, terminate HTTPS, and hide backends, a common web entry point.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#反向代理 #架构
什么是 WebSocket？它和普通 HTTP 请求有什么不同？
What is WebSocket, and how does it differ from normal HTTP?
HTTP 是一问一答、连完就断；WebSocket 先握手再升级成一条长连接，之后服务器可主动随时推消息，适合聊天和实时行情。
HTTP is request-response and closes; WebSocket upgrades to one long-lived connection after a handshake, so the server can push messages anytime, great for chat and live feeds.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#WebSocket #实时
什么是 OSI 七层模型和 TCP/IP 四层模型？
What are the OSI seven-layer and TCP/IP four-layer models?
它们把网络通信拆成层次，每层只管自己的事：从物理信号、网络寻址到应用数据。OSI 是理论七层，TCP/IP 是实际常用的四层。
They split networking into layers, each handling its own job, from electrical signals and addressing to application data. OSI is the 7-layer theory; TCP/IP is the practical 4-layer stack.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#协议栈 #模型
什么是 CDN？为什么看视频和刷网页更快？
What is a CDN, and why does it make videos and pages load faster?
CDN 把内容缓存到离用户近的节点。你访问时从最近的节点取数据，路程短、延迟低，所以加载更快、源站压力也小。
A CDN caches content on servers near users. You fetch from the closest node, so the trip is short and latency low, speeding loads and easing the origin server.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#CDN #加速
TCP 三次握手是怎么回事？
How does the TCP three-way handshake work?
客户端发 SYN 请求连接，服务器回 SYN-ACK 表示收到并同意，客户端再发 ACK 确认。三次往返确保双方收发能力都正常。
The client sends SYN, the server replies SYN-ACK, and the client sends ACK. These three steps confirm both sides can send and receive.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Kurose & Ross,《Computer Networking: A Top-Down Approach》第8版,Pearson,2021
J. F. Kurose and K. W. Ross, Computer Networking, 8th ed., Pearson, 2021
#TCP #握手