A typical connection diagram for Supermicro based platform:
IPMI - is an integrated control and monitoring interface of Supermicro platform
IPMI configuration
A typical connection diagram for Dell r620 based platform:
iDRAC - is an integrated Dell Remote Access Controller: control interface.
The external access network interface sends outbound requests to a cloud platform, netflow traffic transmission and SSH access for tech support, if required. You have to assign the IP address on initial install:
IP address assignment
IN1,2,3 - are dna0;dna2;dna4 respectively. They connect the platform to internal operator's network.
OUT1,2,3 - are dna1;dna3;dna5 respectively. They connect the platform to external network (Internet).