What Port Does The Domain Name System Or DNS Service Use?

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What port is used by the Domain Name System or DNS service?

DNS was designed from the beginning to use UDP and TCP ports 53. 1 , UDP is the default value and falls back to TCP when it cannot communicate over UDP, usually when the packet size is too large to be transmitted in a single UDP packet.

What port does the DNS server use?

The DNS server uses the well-known port 53 for all its UDP operations and as a server port for TCP. Use a random port number greater than 1023 for TCP requests. The DNS client uses a random port greater than 1023 for both UDP and TCP.

What service is port 445?

TCP port 445 is used for direct access to the MS TCP/IP network without using the NetBIOS layer. This service is implemented only in newer versions of Windows, starting with Windows 2000 and Windows XP. The Server Message Block (SMB) protocol is used, among other things, to exchange files in Windows NT/2K/XP.

What is port 80 for?

Port 80 is the port number assigned to the communication protocol widely used on the Internet, Hypertext Transfer Protocol (HTTP). This is the port through which the computer sends and receives web client based messages and web server messages and is used to send and receive HTML pages or data.

What is the main purpose of a DNS server?

DNS translates domain names into IP addresses so that browsers can load Internet resources. Every device connected to the Internet has a unique IP address that other computers use to find the device. DNS servers save people from having to remember IP addresses like 192.168.1.

What types of DNS servers are there?

Three types of DNS servers:

  • DNS stub resolver.
  • Recursive DNS resolver.
  • Authoritative DNS server.

What is port 139 for?

Therefore, SMB requires network ports on the computer or server to communicate with other systems. SMB uses IP port 139 or 445. Port 139: SMB originally ran under NetBIOS using port 139. NetBIOS is a legacy transport layer that allows Windows computers to communicate with each other on the same network.

What is port 139 for?

Port 139 is used for sharing files and printers, but it is the most dangerous port on the Internet. This is because the user’s hard drive is open to hackers.

Are ports 8080 and 80 the same?

No, port 80 and port 8080 are not the same thing. Ports are used to create unique connections and range from 0 to 65535, of which up to 1024 are well-known ports reserved by convention to identify certain types of services on a host. … port 8080 is only the second default option for a web server.

How to know if port 80 is free?

Check the availability of port 80

  1. From the Windows Start menu, select Run.
  2. In the Run dialog box, type: cmd.
  3. Click OK.
  4. In the command window, type: netstat anus.
  5. A list of active connections is displayed. …
  6. Start Windows Task Manager and select the Processes tab.
  7. If you don’t see the PID column, choose Select Columns from the View menu.