總結挑戰 · Summary Challenge

Which three options are UDP benefits when compared to TCP? (Choose three.)與 TCP 相比，UDP 有哪三項優點？（選三項。）

higher performance效能較高lower-overhead data communications between hosts主機間資料通訊的額外負擔較低higher-overhead data communications between hosts主機間資料通訊的額外負擔較高lower-latency data transmission資料傳輸延遲較低higher-latency data transmission資料傳輸延遲較高

Which protocol and port number are used by SSH?SSH 使用哪種通訊協定與連接埠號？

TCP/port 22TCP／連接埠 22UDP/port 161UDP／連接埠 161TCP/port 25TCP／連接埠 25TCP/port 443TCP／連接埠 443

What is the main characteristic of DNS?DNS 的主要特性為何？

automatically assigning an IP address from an IP address pool that the administrator defines從管理員定義的 IP 位址集區中自動指派 IP 位址automatically assigning a domain name from a domain name pool that the administrator defines從管理員定義的網域名稱集區中自動指派網域名稱converting human-readable names of IP end systems into machine-readable IP addresses將人類可讀的 IP 終端系統名稱轉換為機器可讀的 IP 位址forwarding DHCP packets between clients and servers在用戶端與伺服器之間轉發 DHCP 封包

Which Cisco IOS interface command specifies that the interface acquires an IPv4 address through DHCP?哪個 Cisco IOS 介面指令可指定介面透過 DHCP 取得 IPv4 位址？

ip address dhcpip address dhcpdhcp address ipdhcp address ipip helper-addressip helper-addressip address request dhcpip address request dhcp

Which Cisco IOS command displays the services that are running by viewing its open ports?哪個 Cisco IOS 指令可透過檢視開啟的連接埠來顯示正在執行的服務？

show services open-portsshow services open-portsshow control-plane host open-portsshow control-plane host open-portstelnet open-portstelnet open-portsping open-portsping open-ports

What is a major difference between TCP and UDP?TCP 與 UDP 之間最主要的差異為何？

TCP can ensure that the data is delivered, while UDP does not.TCP 能確保資料送達，而 UDP 不能。UDP can ensure that the data is delivered, while TCP does not.UDP 能確保資料送達，而 TCP 不能。TCP exists in the Transport layer of the TCP/IP model, while UDP exists in the Internet layer of the TCP/IP model.TCP 存在於 TCP/IP 模型的傳輸層，而 UDP 存在於 TCP/IP 模型的網際網路層。TCP exists in the Internet layer of the TCP/IP model, while UDP exists in the Transport layer of the TCP/IP model.TCP 存在於 TCP/IP 模型的網際網路層，而 UDP 存在於 TCP/IP 模型的傳輸層。

What are the three main objectives of TCP reliability? (Choose three.)TCP 可靠性的三大目標為何？（選三項。）

detection and retransmission of dropped packets偵測並重新傳送遺失的封包detection and remediation of duplicate or out-of-order data偵測並修正重複或順序錯亂的資料avoidance of congestion in the network避免網路壅塞detection of dropped packets; the application does the retransmission偵測遺失的封包；由應用程式負責重新傳送detection of duplicate or out-of-order data; the application does the remediation偵測重複或順序錯亂的資料；由應用程式負責修正avoidance of delay in the network避免網路延遲

What is session multiplexing?什麼是工作階段多工（session multiplexing）？

a process by which an IP host is able to support multiple sessions simultaneously over multiple links一種讓 IP 主機能同時透過多條鏈路支援多個工作階段的程序a process that is used for congestion avoidance一種用於避免壅塞的程序a process that is used for packet dropping一種用於封包丟棄的程序a process by which an IP host is able to support multiple sessions simultaneously and manage the individual traffic streams over a single link一種讓 IP 主機能透過單一鏈路，同時支援多個工作階段並管理個別流量串流的程序

Which three common applications use TCP? (Choose three.)哪三種常見應用程式使用 TCP？（選三項。）

Which three common applications use UDP? (Choose three.)哪三種常見應用程式使用 UDP？（選三項。）

Which OSI stack layers match the application layer of the TCP/IP stack?TCP/IP 堆疊的應用層對應到 OSI 堆疊的哪些層？

presentation layer, session layer, and transport layer表現層、會議層與傳輸層application layer, presentation layer, session layer, and transport layer應用層、表現層、會議層與傳輸層application layer, presentation layer, and session layer應用層、表現層與會議層network layer and transport layer網路層與傳輸層

Which two characteristics describe HTTP? (Choose two.)以下哪兩項描述了 HTTP 的特性？（選兩項。）

HTTP uses a peer-to-peer model of communication.HTTP 使用對等式（peer-to-peer）通訊模型。HTTP is a stateless protocol.HTTP 是一種無狀態通訊協定。HTTP is using only UDP protocol.HTTP 僅使用 UDP 通訊協定。HTTP is a stateful protocol.HTTP 是一種具狀態通訊協定。HTTP works on the application layer.HTTP 運作於應用層。

Summary Challenge總結挑戰