Physical And Logical Interfaces; Requirements For Active-Passive; Which Physical Interface Is Preferred; Bonded Network Interfaces - HP StorageWorks P4000 User Manual

Physical and logical interfaces

The two NICs in the storage system are labeled as listed in
are bonded for failover, the logical interface is labeled bond0 and acts as the master interface. As
the master interface, bond0 controls and monitors the two slave interfaces which are the physical
interfaces.
Table 20 Bonded network interfaces
Failover name
bond0
eth0 or Motherboard:Port1
eth1 or Motherboard:Port2
The logical master interface monitors each physical slave interface to determine if its link to the device
to which it is connected, such as a router, switch, or repeater, is up. As long as the interface link
remains up, the interface status is preserved.
Table 21 NIC status in Active-Passive configuration
If the NIC status is
Active
Passive (Ready)
Passive (Failed)
If the active NIC fails, or if its link is broken due to a cable failure or a failure in a local device to
which the NIC cable is connected, then the status of the NIC becomes Passive (Failed) and the other
NIC in the bond, if it has a status of Passive (Ready), becomes active.
This configuration remains until the failed preferred interface is brought back online. When the failed
interface is brought back online, it becomes Active. The other NIC returns to the Passive (Ready) state.

Requirements for Active-Passive

To configure Active-Passive:
• Both NICs should be enabled.
• NICs should be connected to separate switches.

Which physical interface is preferred

When the Active-Passive bond is created, if both NICs are plugged in, the SAN/iQ software interface
becomes the active interface. The other interface is Passive (Ready).
For example, if Eth0 is the preferred interface, it will be active and Eth1 will be Passive (Ready). Then,
if Eth0 fails, Eth1 changes from Passive (Ready) to active. Eth0 changes to Passive (Failed).
Once the link is fixed and Eth0 is operational, there is a 30–second delay and then Eth0 becomes
the active interface. Eth1 returns to the Passive (Ready) state.
Table 20
Failover description
Logical interface acting as master
Physical interface acting as slave
Physical interface acting as slave
The NIC is
Currently enabled and in use
Slave to a bond and available for failover
Slave to a bond and no longer has a link
P4000 SAN Solution user guide
on page 89. If both interfaces
89