Networking Question of the Week

Every other week we post TCP/IP, subnetting, and other networking certification questions to help you prep for the exams.

In a router table, you see an entry for 172.16.32.0/20.  What is the mask (in dotted decimal notation)?

  1. 255.255.255.0
  2. 255.255.240.0
  3. 255.255.255.240
  4. 255.255.254.0

 

The correct answer is 2.

The mask in binary is: 11111111111111111111000000000000 (we know there are 20 ones from the /20). In dotted decimal notation that converts to 255.255.240.0.

Related Courses
TCP/IP Networking
Understanding Network Fundamentals

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