Troubleshooting guide

1-5
Cisco Wide Area Application Services Configuration Guide
OL-26579-01
Chapter 1 Configuring AppNav
Information About AppNav
For example, you can use this kind of matching to classify all traffic from a peer device that serves
one branch office.
• 3-tuple of source IP, and/or destination IP, and/or destination port (matches traffic from a specific
application).
For example, you can use this kind of matching to classify all HTTP traffic that uses port 80.
• A mix of one peer device ID and the source IP, and/or destination IP, and/or destination port
(matches application-specific traffic from one site).
For example, you can use this kind of matching to classify all HTTP traffic that is from a peer device
that serves the one branch office.
The class-default class map is a system-defined default class map that is defined to match any traffic. By
default, it is placed in the last rule in each policy to handle any traffic that is not matched by other classes.
Policies
An AppNav Controller matches incoming flows to class maps and the policy rules in a policy associate
class maps with actions, such as distributing a flow to a particular WNG for optimization. The order in
which rules are listed in the policy is important. Starting at the top of the policy, the first rule that
matches a flow determines to which WNG it is distributed.
A policy rule can specify four kinds of actions to take on a flow:
• Specify the primary WNG to which to distribute the flow (required).
• Specify a backup WNG for distribution if the primary WNG is unavailable or overloaded (optional).
The primary WNG receives all traffic until all WNs within the group become overloaded (reach 95
percent of the maximum number of transport flow optimization [TFO] connections) or are otherwise
unavailable, and then traffic is distributed to the backup WNG. If a WN in the first WNG becomes
available, traffic is again distributed there. If all WNs in both WNGs become overloaded, traffic is
passed through unoptimized.
• Monitor the load on the application accelerator that corresponds to the application traffic matched
by the class (optional).
If the monitored application accelerator on one WN in a WNG becomes overloaded (reaches 95
percent of its maximum number of connections), the WN is considered overloaded and traffic is
directed to another WN in the group. If all WNs become overloaded, traffic is distributed to the
backup WNG. This application accelerator monitoring feature is useful for ensuring optimization
for critical applications and is recommended for the MAPI and SMB accelerators.
• Specify a nested policy to apply to the flow (optional).
For more information, see the “Nested Policies” section on page 1-6.
Within a WNG, flows are distributed evenly among WNs. If a WN reaches its maximum capacity or
becomes unavailable, it is not sent new flows. New flows are sent to other available WNs in the WNG
so that they can be optimized successfully.
Note If a WN that is doing MAPI or ICA application acceleration becomes overloaded, flows associated with
existing MAPI and ICA sessions continue to be sent to the same WN due to the requirement that the
same WN handle these types of flows. New MAPI and ICA flows, however, are distributed to other WNs.