CompTIA 220-801 Certification Practice Test

Answer - A - The default subnet mask for the IP address 192.168.10.10 is 255.255.255.0.

Key Takeaway: The method to find out the subnet mask for a given IP address is:

1. Check the class of the IP address given.

2. If asked for a default subnet mask for a particular class of IP, the subnet mask would have as many 255s as the sequence of alphabets. For example, class A will have one 255, class B will have two 255s and class C will have three 255s.