Raritan Computer CC-SG - Manual (Page 165)

C HAPTER 12: A DVANCED A DMINISTRATION 151
the Fully-Qualified Domain Name (FQDN) if a domain server and domain suffix has been
configured.
4. Click either Primary/Backup Mode or Active/Active Mode. A CC-SG provides two
Network Interface Controllers (NIC). The NICs on a G1 or V1 unit are labeled left-to-right,
on the rear of the unit as follows:
M ODEL L EFT - MOST NIC ( PRIMARY INTERFACE ) R IGHT - MOST NIC
G1 LAN1 LAN0
V1 LAN1 LAN2
The NICs on an E1 unit are different, as follows:
M ODEL T OP NIC ( PRIMARY INTERFACE ) B OTTOM NIC
E1 LAN1 LAN2
One interface could be used by itself or both could be used simultaneously. For simplicity,
the discussion below uses LAN1 as left NIC and LAN2 as right NIC. Some internal
diagnostics and messages may refer to these interfaces as “eth0” and “eth1.”
Note: If both interfaces are disconnected, CC-SG restarts.
A. Choose Primary/Backup mode to implement network failover and redundancy. In this mode,
only one NIC is active at a given point of time and only one network IP address assignment is
possible.
Figure 152 Primary/Backup Network
Typically, both NICs are attached to the same LAN sub-network, but different switches (or
hubs) may be used for reliability. When both NICs are used, a level of network redundancy is
provided. For example, if LAN1 is connected and is receiving a Link Integrity signal, CC-SG
uses this NIC for all communications. In the event of a LAN1 failure, if LAN2 is connected,
CC-SG migrates the assigned (possibly by DHCP) IP address to LAN2. LAN2 will be used
until LAN1 is repaired and returned to service. When this happens, CC-SG reverts to using
LAN1.
As long as one interface is viable, a PC client should not notice any disruption in service
during a failure. CC-SG remains at the same logical IP address, but attempts to keep
communication channels and existing sessions up in the event of possible network failures.
All communication (for example, PC client, Raritan device management, cluster peer, etc.) is
carried over this single communication channel that is maintained by both NICs.