System information

Introduction 35
Ethernet Ports on the OnBoard
The secondary Ethernet port on the OnBoard can optionally be configured for
failover, which is also referred to as bonding. Failover is important for high-
availability environments where constant accessibility is required to support
mission-critical applications. Failover automatically redirects traffic from the
primary Ethernet port to the secondary Ethernet port if the primary interface
fails. The primary Ethernet port continues to be monitored, and when it starts
functioning again, traffic is then automatically redirected back through the
primary Ethernet port again. All connection sessions continue without
interruption.
With failover, both the primary and secondary Ethernet ports are assigned a
single IP and single MAC [Ethernet] address.
After failover is enabled, the bonded Ethernet interfaces are referred to as
“bond0.”
For example, when failover is set, the ifconfig command lists bond0
along with eth0 and eth1 as shown in the following screen example. Note
that the “HWaddress” [MAC address] and “inet addr” [IP address] are
identical for bond0, eth0, and eth1.
[root@ONB /]# ifconfig
bond0 Link encap:Ethernet HWaddr 00:60:2E:00:4F:97
inet addr:172.20.0.131 Bcast:172.20.255.255 Mask:255.255.0.0
eth0 Link encap:Ethernet HWaddr 00:60:2E:00:4F:97
inet addr:172.20.0.131 Bcast:172.20.255.255 Mask:255.255.0.0
...
eth1 Link encap:Ethernet HWaddr 00:60:2E:00:4F:97
INET ADDR:172.20.0.131 BCAST:172.20.255.255 MASK:255.255.0.0