ASRock 4X4 BOX-4800U Out-of-Band Management using Realtek DASH
 

Many computing use-cases require out-of-band management. For example, rack-mounted servers have dedicated LAN ports that connect to a baseboard management controller (BMC) chip for this purpose. PCs used in SMBs / SMEs and business applications do not accommodate a dedicated LAN port for this functionality. Instead, one of the in-band NICs (i.e, one used to provide the primary networking functionality of the system) helps in this aspect.

https://www.anandtech.com/show/16319...g-realtek-dash