6.2 HP IBRIX 9000 Storage Network Best Practices Guide (TA768-96069, December 2012)

The VC modules are cross linked through connectors X7 and X8 to provide redundant paths from
the enclosure midplane to the external network. The connection of X7 and X8 is internally
implemented on the enclosure midplane. External cables should not be plugged into VC connections
X7 and X8.
Example of packet traversals
This section provides sample packet traversals through the physical connections to illustrate the
flow of network traffic.
Packet traversing from FSN to external user network:
1. The packet is created in the application layer of the FSN and is destined for a file client on
the user network.
2. The O/S determines by IP address that the user network can be reached through the bond1
interface and queues the packet for that interface.
3. The bond driver determines which of its two underlying physical interfaces are up and
functioning correctly. If both interfaces are available, the packet is sent out over the last working
interface, otherwise it is routed to the working interface. For illustration, assume that the eth1
interface was chosen for transmission to the VC via the enclosure midplane.
4. The VC module in bay 1 receives the packet from the enclosure midplane and determines that
it is meant for the external network. It forwards the packet out the X5 connector (or one of the
other LACP trunked connectors) to the customer network via the customer edge switch.
5. Packet routing from this switch to the file client is completed within the customer’s network.
Packet traversing from FSN to FSN:
1. The packet is created in the application layer of FSN (bay 1) and is destined for FSN (bay
2).
2. The O/S determines by IP address that FSN (bay 2) can be reached through the bond1
interface and queues the packet for that interface.
3. The bond driver determines which of its two underlying physical interfaces to use. For
illustration, assume that the eth2 interface was chosen for transmission to the VC via the
enclosure midplane.
4. The VC module in bay 2 receives the packet from the enclosure midplane and determines that
it is meant for another server in the same enclosure. It forwards the packet via the enclosure
midplane to the eth2 interface of FSN (bay 2).
5. The FSN (bay 2) eth2 physical interface receives the packet from the enclosure midplane.
Since eth2 is a member of bond1, the packet is forwarded to the bond driver for routing to
the application layer.
6. The application layer on FSN (bay 2) receives the packet from the bond1 interface.
Packet traversing from FSN to management network:
1. The packet is created in the application layer of the FSN and is destined for the management
interface of one of the enclosure's SAS interconnect modules.
2. The O/S determines by IP address that the management network can be reached through the
bond0 interface and queues the packet for that interface.
3. The bond driver determines which of its two underlying physical interfaces should be used to
transmit the packet. For illustration, assume that the eth0 interface was chosen for transmission
to the VC via the enclosure midplane.
4. The VC module in bay 1 receives the packet from the enclosure midplane and determines that
it should be routed through the external network. It forwards the packet out the X6 connector,
to the customer’s management network via the customer edge switch.
5. The packet is routed through the customer’s network to the edge switch connected to the
enclosure's active OA module.
40 IBRIX 9730 platform networking