Field Notice: FN - 64197 - WAAS Devices That Run 6.1.1, 6.1.1a, or 6.2.1 Might Have Connections Reset - Software Fix Available

NOTICE:

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Revision History

Products Affected

Problem Description

After six to eight weeks of system uptime, Cisco Wide Area Application Services (WAAS) devices that run Software Version 6.1.1, 6.1.1a, or 6.2.1 start to retransmit packets quickly between peers. Due to issues with the timer scheduler, timers misfire before their scheduled times. This results in immediate retransmissions of TCP packets and might cause connection resets.

When this condition is triggered, traffic on the WAN increases. Not all connections might fail during this condition, but this can cause a network outage.

Background

6.1.1, 6.1.1a, and 6.2.1 WAAS software timer scheduler compares the current and scheduled times and incorrectly determines that all the scheduled timers have elapsed. All the timers are then executed without delay.

Problem Symptoms

Access to WAAS devices will be very slow due to the access link congested by the fast retransmission of the packets. Central Manager will report optimized traffic volume much greater than the original traffic. 

Workaround/Solution

In order to correct this issue, complete these steps:

1. Reboot the WAAS devices - the problem will likely recur after a similar time has elapsed.
2. Upgrade to WAAS 6.2.1a or later (recommended). WAAS software can be found on the WAAS Download Software page.

CDETS

To follow the bug ID link below and see detailed bug information, you must be a registered customer and you must be logged in.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

• Open a service request on Cisco.com
• By email
• By telephone

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