What this means
The IEEE assigned the MA-L block 587521 to CJSC RTSoft. Every network interface they manufacture under this block has a MAC address beginning with these digits, followed by a unique per-device identifier. If a device on your network shows a MAC starting 58:75:21, it is CJSC RTSoft hardware.
Frequently Asked Questions
Who owns MAC prefix 587521?
587521 is registered to CJSC RTSoft in the IEEE MA-L registry.
What does the MA-L registry type mean?
An MA-L assignment, the IEEE's original OUI format, gives the vendor the first three octets and 16,777,216 device addresses under them. CJSC RTSoft's block covers 16,777,216 addresses.
What devices use 587521?
Any network device with a MAC address starting 58:75:21 was manufactured by or for CJSC RTSoft.