Write the subnet mask for the prefix /26 in dotted-quad notation.
LPIC-1 Exam 102-500, objective 109. Networking fundamentals medium
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Answer
Type the answer.
Accepted answer
255.255.255.192
Case sensitive — Linux is, and grading LS as ls would teach a falsehood.
Why
A /26 sets the first 26 bits: the fourth octet is 11000000 in binary, which is 192. That leaves 6 host bits, so each /26 block holds 64 addresses (62 usable) and the blocks begin at .0, .64, .128 and .192. The last-octet values for /25 to /32 run 128, 192, 224, 240, 248, 252, 254, 255.
Where this comes from
- Cited
- LPI exam objective 109.1
- What it says
- Convert a CIDR prefix length to a dotted-quad subnet mask.
Practise this
Reading one question is not practice. The trainer will draw a set from objective 109 and space the ones you get wrong.