Cisco Wide Area Application Engine 612 Manual de usuario descargar pdf (Pagina 32)

106 Chapter 4: Network Integration and Interception

Physical inline interception is an attractive option for situations where it is not possible or

ideal to run WCCPv2. It is also possible that the networking equipment at a site is provided

and managed by a managed service provider (MSP). The MSP may not be able to conﬁgure

or support a WCCPv2 solution on the managed devices.

To support physical inline interception, the WAE requires a separate inline module. The

inline module is a 4-port, fail-to-wire NIC that supports two separate inline groups. Each

inline group has a synchronous pair of inline ports that interconnect two network elements.

Trafﬁc entering one inline port is optimized by WAAS (when applicable) and switched out

the opposite inline port in the same group. The inline group functions like a transparent

Layer 2 bridge.

By providing two inline groups on a single module, the WAE can support designs where

multiple paths out of a site exist for redundancy and load sharing. Each unique path is

connected to the WAE through a separate inline group. Figure 4-14 shows a sample remote

site topology with multiple WAN routers and a single WAE deployed with inline interception.

Figure 4-14 Physical In-Path Deployment Using Multiple Routers

As the arrows in Figure 4-14 indicate, trafﬁc can enter or leave the site through either router.

Even though the same ﬂow enters the site through one inline group and exits the site through

another inline group, the connection will still be optimized. The optimized connection state

is not tied to a physical interface, but is tracked for the WAE as a whole independent of the

interfaces traversed by the trafﬁc.

Each inline group functions in one of two operating modes:

• Intercept operating mode: Trafﬁc entering the inline group is evaluated against the

Application Trafﬁc Policy (ATP) for optimization.

• Bypass operating mode: All trafﬁc entering the inline group is bridged without any

optimization.

The bypass operating mode is designed to allow the WAE to continue passing trafﬁc if the

WAE looses power. A keepalive mechanism between the network drivers and the inline

module is used to determine if the WAE is functioning properly and can optimize

connections.

WAN

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Cisco Wide Area Application Engine 612 Manual de usuario Pagina 32