HP StorageWorks Enterprise File Services WAN Accelerator - Manual (Page 66)

66 C ONFIGURING THE HP EFS WAN A CCELERATOR
‹ “Enabling Connection Forwarding” on page 68
‹ “Enabling Encryption” on page 70
‹ “Enabling Failover and Data Store Synchronization” on page 73
‹ “Setting Peering Rules” on page 79
‹ “Enabling Quality of Service” on page 81
‹ “Modifying a QoS Class” on page 85
‹ “Setting QoS Marking” on page 87
‹ “Modifying QoS Marking Descriptions” on page 89
‹ “Modifying Service Ports” on page 90
‹ “Enabling Simplified Routing” on page 92
‹ “Enabling WCCP Groups” on page 94
‹ “Modifying WCCP Group Settings” on page 96
Enabling
Asymmetric
Routing Auto-
Detection You enable asymmetric route auto-detection in the Advanced Networking -
Asymmetric Routing page. Asymmetric route auto-detection detects and reports
asymmetric routing conditions and caches this information to avoid losing
connectivity between a client and a server.
When HP EFS WAN Accelerators are deployed in a network, all TCP traffic must flow
through the same HP EFS WAN Accelerators in the forward and reverse direction. If
traffic flows through an HP EFS WAN Accelerator in one direction and not the other,
then TCP clients are unable to make connections to TCP servers. When deploying HP
EFS WAN Accelerators into redundant networks, there is a possibility of traffic taking
different forward and return paths so that traffic in one direction goes through HP EFS
WAN Accelerators but traffic in the reverse direction does not.
If asymmetric routing is detected, the pair of IP addresses, defined by the client and
server addresses of this connection, is cached on the HP EFS WAN Accelerator.
Further connections between these hosts are not optimized until that particular
asymmetric routing cache entry times out.
Detecting and caching asymmetric routes does not optimize these packets. If you want
to optimize asymmetric routed packets you must make sure that packets going to the
WAN always go through an HP EFS WAN Accelerator either by using a multi-port HP
EFS WAN Accelerator, connection forwarding, or using external ways to redirect
packets, such as WCCP or PBR.
For detailed information, see “Enabling Connection Forwarding” on page 68 or the HP
StorageWorks Enterprise File Services WAN Accelerator Deployment Guide.