Guest

Cisco Traffic Anomaly Detectors

Field Notice: FN - 62741 - U.S. Daylight Savings Time (DST) Changes - All DDOS Guard and Detector Appliance Versions - Configuration Change or Upgrade Required


March 8, 2007

NOTICE:

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.


Products Affected

Products Affected

ADXT-5600-GET-A-K9

ADXT-5600-MMF-B-K9

AGXT-5650-MMF-B-K9

AGXT-5650-GET-A-K9

Problem Description

Note: This issue affects only Guard and Detector appliances. Network Modules are not affected.

New U.S. Daylight Savings Times rules go into effect in March 2007. Consequently, customers whose network components rely on the default U.S. clock settings will be affected by the following problem.

For operating systems that have not been updated with the new U.S. DST policy changes, timestamps will exhibit a one hour time clock offset lasting three weeks beginning at 2:00 A.M. on the second Sunday in March of 2007. They will also exhibit a one hour time clock offset lasting one week beginning at 2:00 A.M. on the first Sunday in November.

Any time-dependent applications not running the upgraded version of software will be affected by this problem.

Table 1 - Summary of changes to Daylight Savings Time

Event

Prior to 2007

Year 2007 and After

Start

First Sunday in April

Second Sunday in March

End

Last Sunday in October

First Sunday in November

The Energy Policy Act of 2005, bill number H.R.6.ENR, can be found at The Library of Congress, THOMAS. Search for "daylight savings" to find the Act in various stages.

Background

On August 8, 2005, President Bush signed into law the Energy Policy Act, which extends Daylight Saving Time (DST) by four weeks from the second Sunday of March to end on the first Sunday of November. The Secretary of Energy will report the impact of this change to Congress, and then Congress retains the right to resume the 2005 Daylight Saving Time schedule once the Department of Energy study is complete. This law takes effect March 1, 2007.

Problem Symptoms

Systems without the DST configuration change will be incorrect by one hour during the new extended DST window.

This will affect scheduled tasks, time of day reporting, and time of day display.

Workaround/Solution

Users should upgrade the system to firmware version 6.0(5) to incorporate the new DST configuration settings. The software can be downloaded from CCO at the following locations:

Anomaly Guard: Cisco Guard Appliance Cryptographic Software Download (registered customers only) page.

Anomaly Detector: Cisco Anomaly Detector Appliance Cryptographic Software Download (registered customers only) page.

Alternatively, users may manually configure the clock setting on the appliance to conform to the new time of day settings at the time that the new law goes into effect - beginning at 2:00 A.M. on the second Sunday in March of 2007.

When the clock is configured manually, note that Border Gateway Protocol (BGP) sessions will be dropped and re-established. Additionally, if using Network Time Protocol (NTP) Services, the user should also set the appropriate timezone, so that NTP does not reconfigure the clock to the original non-DST time.

Revision History

Revision

Date

Comment

1.0

08-MAR-2007

Initial Public Release

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:

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