HP StorageWorks Enterprise File Services WAN Accelerator 3.0.4 deployment guide (AG421-96001, March 2007)

32 3 - VIRTUAL IN-PATH NETWORK DEPLOYMENTS
 Layer-4 Switch. You enable Layer-4 switch (or server load-balancers) support
when you have multiple HP EFS WAN Accelerators in your network to manage
large bandwidth requirements.
 Hybrid. A hybrid deployment is a deployment in which the HP EFS WAN
Accelerator is both in-path and out-of-path. A hybrid deployment is useful where
the HP EFS WAN Accelerator must be referenced from remote sites as an out-of-
path device (for example, to avoid mistaken auto-discovery or to bypass
intermediary HP EFS WAN Accelerators). For detailed information, see Chapter
4, “Out-of-Path Network Deployments.”
 Policy-Based Routing (PBR). PBR enables you to redirect traffic to an HP EFS
WAN Accelerator that is configured as an out-of-path device. PBR allows you to
define policies to route packets instead of relying on routing protocols. You
define policies to redirect traffic to the HP EFS WAN Accelerator and policies to
avoid loop-back. For detailed information, see Chapter 6, “Policy-Based Routing
Deployments.”
 WCCP. WCCP was originally implemented on Cisco routers, multi-layer
switches, and Web caches to redirect HTTP requests to local Web caches (Version
1). Version 2, which is implemented on HP EFS WAN Accelerators, can redirect
any type of connection from multiple routers or Web caches. For example, if you
have multiple routers or if there is not a virtual place for the HP EFS WAN
Accelerator, you can place the HP EFS WAN Accelerator to be virtually in-path
through the router so that they work together. Typically, you configure WCCP on
the client-side HP EFS WAN Accelerator. For detailed information, see Chapter
7, “WCCP Deployments.”
In-Path, Load Balanced, Layer-4 Switch
An in-path, load-balanced, Layer-4 switch deployment serves high traffic
environments or environments with large numbers of active Transmission Control
Protocol (TCP) connections. It handles failures, scales easily, and supports all
protocols.
When you configure the HP EFS WAN Accelerator using a Layer-4 switch, you define
the HP EFS WAN Accelerators as a pool where the Layer-4 switch redirects client and
server traffic.
Only one WAN interface on the HP EFS WAN Accelerator is connected to the Layer-4
switch, and the HP EFS WAN Accelerator is configured to send and receive data
through that interface.