Cisco Aironet 1200 Series

July 3, 2002

• More Field Notices

Products Affected

• AIR-AP1200

• AIR-AP1220B-A-K9

• AIR-AP1220B-E-K9

Problem Description

Cisco Aironet 1200 Series access points may hang or reboot when they receive a burst of packets over the Ethernet port. A power cycle might be needed to bring the units back up.

Background

This issue can occur when any extended burst of traffic (39 frames or more in less than one microsecond) is received by the Ethernet port on the Cisco Aironet 1200 Series Access Point (AP). One example of such a burst is seen when over 30 Cisco Aironet APs are located on the same multicast domain. The APs will create the burst when one AP requests an update and all the other APs respond. This issue may also be seen on any very busy network.

Problem Symptoms

The following messages may appear:

Message 1:

machine check
 Exception next instruction address: 0x000359bc
 Machine Status Register: 0x00029200
 Condition Register: 0x48000042
 Bus Error Adress Register: 0x02000004
 Bus Error Syndrome Register: 0x0c000000
 Task: 0xe3bb00 "tNetTask"

Message 2:

*** Restarting System in 5 seconds...

 machine check
 Exception next instruction address: 0x001f2fe0
 Machine Status Register: 0x00029200
 Condition Register: 0x22242048
 Bus Error Adress Register: 0x0163ca18
 Bus Error Syndrome Register: 0x0c000000
 Task: 0xbd6858 "tDhcpcTask"
     
     
 2002/06/06 10:44:28 (Warning): Routine 
"SysIntegrityTaskBody" is attempting to recover the 
forwardTbl Guard semaphore

Workaround/Solution

Following a power cycle to bring the unit back up, upgrade the access point firmware to release 11.42T, available for download in the Cisco Software Center (registered customers only) .

Upgrade instructions are detailed in the release notes for this firmware version, which are also located on the same download page.

DDTS

To follow the bug ID link below and see detailed bug information, you must be a registered user 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