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Cisco IPS 4200 Series Sensors

Field Notice: FN - 62732 - U.S. Daylight Savings Time (DST) Changes - All IPS Versions - Configuration Validation or Possible Upgrade Required


Revised March 9, 2007

March 7, 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

Product

ASA - ASA-SSM-AIP-10-K9

ASA - ASA-SSM-AIP-20-K9

4215 - IDS-4215-K9

4230 - IDS-4240-K9

4235 - IDS-4235-K9

4255 - IDS-4255-K9

4260 - IPS-4260-K9

IDS - IDS-4250-XL-K9

IDS - NM-CIDS-K9

IDS - WS-SVC-IDS2-BUN-K9

IDS

IDSM2

Problem Description

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 for one week beginning at 2:00 A.M. on the first Sunday in November.

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

Workaround/Solution

Intrusion Prevention Systems (IPS) Version 6.0(1) users who did not upgrade from a previous version are not affected by this issue. The defaults have been properly chosen at the time of manufacture.

IPS version 6.0(1) customers who upgraded from previous versions should verify the configuration setting as described below.

IPS Version 5.1(5) users are not affected by this issue.

IPS Versions prior to 5.1(5) should upgrade to version 5.1(5).

Customers who do not wish to upgrade for the DST issue may also use the CLI command sequence below to verify and/or set the configuration manually.

CLI sequence To display current DST setting:

sensor# sh clock det 
*07:26:53 UTC Fri Mar 02 2007 
No time source 
Summer time starts 02:00:00 UTC Sun Mar 11 2007 Summer time stops 02:00:00 UTC Sun Nov 04 2007 


sensor(config-hos-rec)# show set 
recurring 
----------------------------------------------- 
offset: 60 minutes 
summertime-zone-name: CDT 
start-summertime 
----------------------------------------------- 
month: march 
week-of-month: second 
day-of-week: sunday 
time-of-day: 02:00:00 
----------------------------------------------- 
end-summertime 
----------------------------------------------- 
month: november 
week-of-month: first 
day-of-week: sunday 
time-of-day: 02:00:00 
----------------------------------------------- 
-----------------------------------------------

If the daylight savings time dates do not match the above sequence, users may correct the entries with the following command sequence.

CLI sequence to set summertime defaults (if it has never been configured):

sensor# conf t 
sensor(config)# ser host 
sensor(config-hos)# summertime recurring 
sensor(config-hos-rec)# summertime-zone-name CDT 
sensor(config-hos-rec)# ex 
sensor(config-hos)# ex 
Apply Changes?[yes]: 
Warning: Reboot is required before the configuration change will take effect 
Warning: The node must be rebooted for the changes to go into effect. 
Continue with reboot? [yes]: 



CLI sequence to set updated summertime defaults (if it has been set before):

sensor# conf t 

sensor(config)# ser host 

sensor(config-hos)# summertime recurring 

sensor(config-hos-rec)# default end 

sensor(config-hos-rec)# default start 

sensor(config-hos-rec)# ex 

sensor(config-hos)# ex 

Apply Changes?[yes]: 

Warning: Reboot is required before the configuration change will take effect 
Warning: The node must be rebooted for the changes to go into effect. 
Continue with reboot? [yes]:

CLI sequence to set the time of day clock:

sensor# clock set ? 

hh:mm[:ss] 24 hour current time setting relative to configured timezone.

Revision History

Revision

Date

Comment

1.1

09-MAR-2007

Added CLI sequence to set the time of day clock to the Workaround/Solution section.

1.0

07-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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