A number from 0 to 65535 used by TCP and UDP to identify which application on a host the traffic is for. Ports 0–1023, such as 80 for HTTP, 443 for HTTPS and 53 for DNS, are called well-known ports.
Japanese name: ポート番号
Port number appears in 3 practice questions across 2 topics, including Web Technology Basics, Computer Networking Basics.
Field: Computer Networking Basics
Answer: A. HTTP 80, HTTPS 443, DNS 53
A port number is a 16-bit number from 0 to 65535 that identifies which application on a host, reached by IP address, the traffic is for. Ports 0–1023 are called well-known ports and are assigned to major services. Typical ones are HTTP 80, HTTPS 443, DNS 53, SSH 22 and SMTP (mail transfer) 25. The client side uses a number chosen by the OS each time (an ephemeral port) as its source port. Services can run on non-standard numbers; 8080 is often used for web development or proxy servers, but then the connecting side has to specify the number.
Answer: C. #install
This URL consists of the scheme (https), the host name (www.example.com), the port number (8443; if omitted, 443 for https), the path (/docs/guide.html), the query (lang=ja) and the fragment (install). The browser uses the port number to decide where to connect and sends the path and query to the server in the request, but it does not send the fragment after #. The fragment is used only inside the browser, for example to move to the position of the element with id="install" in the page.
A port number is a 16-bit number from 0 to 65535 that identifies which application on a host, reached by IP address, the traffic is for.
Which correctly pairs protocols with the standard port numb…This URL consists of the scheme (https), the host name (www.example.com), the port number (8443; if omitted, 443 for https), the path (/docs/guide.html), the query (lang=ja) and the fragment (install).
A browser opens https://www.example.com:8443/docs/guide.htm…An origin is determined by the combination of three things, the scheme, the host name and the port number, and two URLs have the same origin only when all three match.
Under the browser's same-origin policy, which of the follow…As an Amazon Associate I earn from qualifying purchases.
HTTP (Hypertext Transfer Protocol) DNS (Domain Name System) SSH Same-origin policy ARP CIDR CSMA/CA Default gateway DHCP MAC address