How link aggregation dynamic mode bonding works, Which physical interface is preferred, Which physical interface is active – HP LeftHand P4000 Virtual SAN Appliance Software User Manual
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Figure 27 Active-Passive failover in a four-switch topology
1. Servers
2. HP P4000
3. Storage cluster
4. GigE trunk
5. Active path
6. Passive path
illustrates the Active-Passive configuration in a four-switch topology.
How link aggregation dynamic mode bonding works
Link Aggregation Dynamic Mode allows the storage system to use both interfaces simultaneously
for data transfer. Both interfaces have an active status. If the interface link to one NIC goes offline,
the other interface continues operating. Using both NICs also increases network bandwidth.
Requirements for link aggregation dynamic mode
To configure Link Aggregation Dynamic Mode:
•
Both NICs should be enabled.
•
NICs must be configured to the same subnet.
•
NICs must be connected to a single switch that is LACP-capable and supports 802.3ad link
aggregation. If the storage system is directly connected to a server, then the server must support
802.3ad link aggregation.
Which physical interface is preferred
Because the logical interface uses both NICs simultaneously for data transfer, neither of the NICs
in an aggregation bond is designated as preferred.
Which physical interface is active
When the Link Aggregation Dynamic Mode bond is created, if both NICs are plugged in, both
interfaces are active. If one interface fails, the other interface continues operating. For example,
suppose Eth0 and Eth1 are bonded in a Link Aggregation Dynamic Mode bond. If Eth0 fails, then
Eth1 remains active.
Once the link is fixed and Eth0 is operational, it becomes active again. Eth1 remains active.
Configuring network interface bonds
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