Cisco 3700 Series Multiservice Access Routers

Revised April 26, 2006

October 14, 2003

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

• CISCO3745-CHAS+MP=

Serial Numbers

To view a list of serial numbers included in the special image, download the file from the Cisco FTP site. The list is not a representation of affected units. To determine if your router is affected refer to the Problem Symptom section of this field notice.

Problem Description

Cisco has discovered a manufacturing anomaly on the Cisco 3745 production line. A number of Cisco3745 Chassis/Mid-planes do not have a Burned-in MAC Address (BIA) programmed into the mid-plane EEPROM cookie. The issue described in this field notice is specific to 3745 and no other routers are affected. The 3745s on-board Fast Ethernet ports Burned-in MAC Address (BIA) can change with each reload of the unit. The changing MAC address is expected behavior on the 3745 when a MAC address is not obtained from the mid-plane EEPROM. MAC addresses assigned to the Fast Ethernet ports in this state are from an internal pool. In some incidents users may encounter duplicate MAC address when multiple Cisco 3745s are deployed on the same LAN segment. In other instances users may notice that the chassis serial number is not being displayed.

Background

This issue has been linked to a manufacturing anomaly for a particular set of Cisco 3745s. This issue was originally uncovered in May 2003 and traced back to the 3rd week of February 2003. More recently in Jan 2006 another group of serial numbers was identified and traced to units manufactured in late 2005. The root cause for both incidents was identified as a mis-programmed manufacturing integrated test script. This script and processes have been corrected and applied.

Problem Symptoms

Most commonly the issue is seen when the Fast Ethernet burned in MAC address (BIA) changes on each reload. In deployments with multiple Cisco 3745s on the same Ethernet segment a duplicate MAC address conflict can occur. Below is an example of a router that changes after reload.

Router-gw1# show interface fast 0/0
FastEthernet0/0 is up, line protocol is up
Hardware is Gt96k FE, address is 0002.2cc2.4c00 (bia 0002.2cc2.4c00)

After reload the BIA address will change:

Router-gw1#show interface fast 0/0
FastEthernet0/0 is up, line protocol is up
Hardware is Gt96k FE, address is 0002.2cc0.8100 (bia 0002.2cc0.8100)

If this symptom is observed on a 3745 verify if the "Chassis MAC Address" has been programed into the EEPROM cookie by issuing the IOS command show diag. Refer to the example below for appropriate output modifiers. Output modifiers are case sensitive.

Example of router with a properly programmed MAC address:

RouterRouter#show diag | include Chassis MAC Address
Chassis MAC Address: 000d.29f8.64d0

Example of a router without a properly programmed MAC address:

Router#show diag | include Chassis MAC Address
NO VALUE RETURNED

Workaround/Solution

WorkAround:

Use the IOS CLI to set the MAC address for the on-board Fast Ethernet ports. This will not set the mid-plane MAC address but will stop the router from changing the MAC address after each reload. The example below shows the IOS command line interface for setting the MAC address with the command mac-address:

Router#config t
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#interface fa0/0
Router(config-if)#mac-address ?
  H.H.H  MAC address

Solution:

Use the special IOS at the bottom of this field notice to program the correct MAC-Address on the affected units. The special image will automatically program units without a properly assigned BIA and will not do anything to units which already have a valid MAC Address programmed. The special IOS program validates the chassis Serial Number and MAC Addresses for all affected units. For a list of serial numbers included in the special image, refer to the Serial Numbers section in this Field Notice. The special image is not intended for use in production environments and will return the router to a ROMMON prompt after running. Steps for using the special image are below. It is recommended to use a direct console connection for this function.

1. Download the special IOS using the link at the bottom of this field notice. .

2. Copy the special image to the router. TFTP the special IOS image into the Compact Flash of the 3745.

3. Make configuration changes to load the image. Change the global boot statement with the IOS configuration command boot system flash to load the special IOS Image. Verify the running configuration and save it to memory. Below are examples of the commands.

   Router#config t
   Enter configuration commands, one per line. End with CNTL/Z.
   Router(config)#boot system flash:c3745-ipbase-mz.macaddr
   Router(config)#^Z
   Router#show run | inc boot system
   boot system flash:c3745-ipbase-mz.macaddr
   Router#write mem
   Building configuration...
   [OK]
   Router#
   
   

4. Restart the router. The special IOS image will run and check for a properly assigned MAC address. If the units does not have a properly assigned MAC address the IOS will automatically program the specific MAC address for that unit after the serial number is validated. While consoled into the unit you will be able to see dialog from the routers console port.

   Once the router has performed the programming the MAC address it will display one of two messages before going to a ROMMON prompt.

   If the router was missing the MAC address, the following message is displayed:

   MAC address cookie not OK, updating ...
   MAC address update ... SUCCESS
   MAC block size update ... SUCCESS
   MAC address cookie update successful
   

   If the router already has a MAC address on the Mid-plane the router will display this message:

   MAC address cookie OK, nothing to do
   

5. Revert to production IOS. Boot the router from the ROMMON prompt and load the production IOS using the ROMMON boot command. Refer to the document ROMMON Recovery for the Cisco 3700 Series Routers for ROMMON CLI commands and syntax.

6. Clean up. Delete the special image from flash, change the boot system flash statement in global configuration and save the configuration.

Special Software Download

Download the special Cisco IOS Software image from the Cisco Software FTP site.

Revision History

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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