HP StorageWorks Enterprise File Services WAN Accelerator 2.1.5 deployment guide (June 2006)

HP STORAGEWORKS ENTERPRISE FILE SERVICES WAN ACCELERATOR 2.1.5 DEPLOYMENT GUIDE 41
5 - CONFIGURING CONNECTION
F
ORWARDING
If there are more than two possible paths, additional HP EFS WAN Accelerators must
be installed on each path and configured as neighbors. Neighbors receive information
in parallel (the delay introduced at connection set up is equal to the time it takes to get
an acknowledgement from the furthest neighbor).
If one of the neighbor HP EFS WAN Accelerators reaches its optimization capacity
limit, that HP EFS WAN Accelerator will not accept new connections, but it redirects
packets to other neighbors for optimization.
One-to-One Failover Deployment
To ensure optimization in the event of a failure, a backup HP EFS WAN Accelerator
can be added to each neighbor HP EFS WAN Accelerator in a one-to-one failover
configuration.
In Figure 5-2 there are two HP EFS WAN Accelerators on each path that are
configured in a one-to-one failover mode. Each HP EFS WAN Accelerator must be a
neighbor of the master and backup HP EFS WAN Accelerators on the other paths.
Figure 5-2. One-to-One Failover Deployment
HP EFS WAN Accelerator-2 and HP EFS WAN Accelerator-2B are configured as
neighbors of HP EFS WAN Accelerator-1 which exchanges connection information
with both of them so that if either HP EFS WAN Accelerator-2 or HP EFS WAN
Accelerator-2B fails, the other redirects packets to HP EFS WAN Accelerator-1.
In Figure 5-2, packets from the server are redirected by HP EFS WAN Accelerator-2B
unless it fails in which case they are redirected by HP EFS WAN Accelerator-2.
As long as one of the two failover HP EFS WAN Accelerators on each path is up,
connections are intercepted. If the two HP EFS WAN Accelerators on the same path
fail, connections stop being intercepted and optimized.
Configuring Connection Forwarding
The following section describes the basic steps for configuring connection forwarding.