CompTIA Tech+ (FC0-U71)IT Concepts and TerminologyMedium
A network administrator needs to represent a subnet mask in hexadecimal format. Given the subnet mask 255.255.255.0, what is its correct hexadecimal representation?
- AFFFFFF00
- BFF.FF.FF.00
- CFFFF.FF00
- DFF.FF.FF.0
Show answer & explanationAnswer & explanation
Correct answer: A. FFFFFF00
Each octet of the subnet mask is converted from decimal to hexadecimal. 255 in decimal is FF in hexadecimal. So, 255.255.255.0 becomes FF.FF.FF.00. When concatenated without dots, it is FFFFFF00.
Why the other options are wrong
- B. While the individual octet conversions are correct, the dots are typically omitted when representing a full 32-bit hexadecimal number like a subnet mask.
- C. Uses a non-standard notation for hexadecimal representation and is missing leading zeros for the last octet.
- D. The last octet '0' should be '00' in hexadecimal to maintain two digits per octet for consistency and proper representation.
Decimal to Hexadecimal Conversion
The process of changing a base-10 number to its equivalent base-16 representation, using digits 0-9 and letters A-F.
- Hexadecimal uses 16 unique symbols (0-9, A-F).
- Each hexadecimal digit represents four binary bits.
- Often used in computing for memory addresses, color codes, and network masks.
Memory trick: De-Hex Your Net Masks!