Redundant Net Unit
A redundant Net Unit has two redundant switches. The SE servers SE /390 have a redundant Net Unit already in the basic configuration. The redundant Net Unit is optional for the SE x86.
On a redundant Net Unit the ports are monitored, and when an active uplink port fails, the remaining port is switched to. When the LAN segment concerned fails, the downtime is consequently reduced to the switchover time.
HNC (High-speed Net Connect) on the SE /390
The High-speed Net Connect (HNC for short) connects the Server Unit /390 with the LAN. Furthermore, as net client the HNC permits access to the Net-Storage. The SE servers SE /390 therefore incorporate an HNC in their basic configuration.
Redundancy of the HNC is an optional feature. Up to four HNCs can be integrated.
Further information on the HNC is provided in the "Server Unit /390" Operating Manual [2].