Troubleshooting guide

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Cisco Wide Area Application Services Configuration Guide
OL-26579-01
Chapter 1 Planning Your WAAS Network
Supported Methods of Traffic Redirection
Supported Methods of Traffic Redirection
In a WAAS network, traffic between the clients in the branch offices and the servers in the data center
can be redirected to WAEs for optimization, redundancy elimination, and compression. Traffic is
intercepted and redirected to WAEs based on policies that have been configured on the routers. The
network elements that transparently redirect requests to a local WAE can be a router using WCCP
version 2 or PBR to transparently redirect traffic to the local WAE or a Layer 4 to Layer 7 switch (for
example, the Catalyst 6500 series Content Switching Module [CSM] or Application Control Engine
[ACE]).
Alternately, a WAE that has the Cisco WAE Inline Network Adapter or Cisco Interface Module installed
can operate in inline mode and receive and optimize traffic directly before it passes through the router.
In an AppNav deployment, an AppNav Controller in the data center receives intercepted traffic through
WCCP, PBR, or inline mode and distributes it to WAAS nodes that optimize the traffic. For more
information on an AppNav deployment, see Chapter 1, “Configuring AppNav.”
This section contains the following topics:
• Advantages and Disadvantages of Using Inline Interception, page 1-19
• Advantages and Disadvantages of Using WCCP-Based Routing, page 1-20
• Advantages and Disadvantages of Using PBR, page 1-21
• Configuring WCCP or PBR Routing for WAAS Traffic, page 1-22
For detailed information about how to configure traffic interception for your WAAS network, see
Chapter 1, “Configuring Traffic Interception.”
Advantages and Disadvantages of Using Inline Interception
Inline interception requires using a WAE appliance that has the Cisco WAE Inline Network Adapter,
Cisco Interface Module, or Cisco AppNav Controller Interface Module installed. In inline mode, the
WAE can physically and transparently intercept traffic between the clients and the router. When using
this mode, you physically position the WAE device in the path of the traffic that you want to optimize,
typically between a switch and a router.
Because redirection of traffic is not necessary, inline interception simplifies deployment and avoids the
complexity of configuring WCCP or PBR on the routers.
The inline adapter or module contains one or more pairs of LAN/WAN Ethernet ports each grouped into
an inline or bridge group interface. If the inline adapter or module has multiple pairs of ports, it can
connect to multiple routers if the network topology requires it.
The inline or bridge group interface transparently intercepts traffic flowing through it or bridges traffic
that does not need to be optimized. It also uses a mechanical fail-safe design that automatically bridges
traffic if a power, hardware, or unrecoverable software failure occurs.
Note AppNav Controller Interface Modules do not support automatic bypass mode to continue traffic flow in
the event of a failure. For high availability, two or more AppNav Controller Interface Modules should
be deployed in an AppNav cluster. For more information on using inline mode with the AppNav solution,
see Chapter 1, “Configuring AppNav.”
You can configure the inline or bridge group interface to accept traffic only from certain VLANs; for all
other VLANs, traffic is bridged and not processed.