Cisco uBR900 Series Cable Access Routers

Field Notice: UBR904 Duplicate MAC Addresses

August 27, 1998

Products Affected

  • Cisco UBR904-US: UBR904 4 Port SOHO Router/Cable Modem

  • Cisco UBR904-RES: UBR904 4 Port SOHO Router/Cable Modem

Affected Serial Numbers

Serial Numbers

FAA0227Q00S, FAA0227Q00W, FAA0227Q010, FAA0227Q011, FAA0227Q015, FAA0227Q018, FAA0227Q01B, FAA0227Q01D, FAA0227Q01G, FAA0227Q01R, FAA0227Q01V, FAA0227Q02D, FAA0227Q02E, FAA0227Q02P, FAA0227Q02S, FAA0227Q02V, FAA0227Q02Z, FAA0227Q032, FAA0227Q039, FAA0227Q03B, FAA0227Q03G, FAA0227Q041, FAA0227Q04D, FAA0227Q04H, FAA0227Q04L, FAA0227Q04M, FAA0227Q057, FAA0227Q058, FAA0227Q05D, FAA0227Q05G, FAA0227Q05M, FAA0227Q05P, FAA0227Q05S, FAA0227Q05Z, FAA0227Q062, FAA0227Q063, FAA0227Q069, FAA0227Q06A, FAA0227Q06E, FAA0227Q06P, FAA0227Q06S, FAA0227Q079, FAA0227Q07Q, FAA0227Q07Z, FAA0227Q084, FAA0227Q08K, FAA0227Q08L, FAA0227Q08N, FAA0227Q091, FAA0227Q09M, FAA0227Q0A2, FAA0227Q0AB, FAA0227Q0B3, FAA0227Q0BN, FAA0227Q0BP, FAA0227Q0C0, FAA0227Q0C4, FAA0227Q0CK, FAA0227Q0CL, FAA0227Q0CV, FAA0227Q0CW, FAA0227Q0D0, FAA0227Q0DE, FAA0227Q0ET, FAA0227Q0F6, FAA0227Q0FB, FAA0227Q0FP, FAA0227Q0FW, FAA0227Q0G3, FAA0227Q0GH, FAA0227Q0GM, FAA0227Q0GX, FAA0227Q0HA, FAA0227Q0HC, FAA0227Q0HL, FAA0227Q0HM, FAA0227Q0HS, FAA0227Q0HT, FAA0227Q0JB, FAA0227Q0JS, FAA0227Q0K0, FAA0227Q0KC, FAA0227Q0KE, FAA0227Q0KH, FAA0228Q001, FAA0228Q003, FAA0228Q00A, FAA0228Q00L, FAA0228Q00M, FAA0228Q00Z, FAA0228Q013, FAA0228Q014, FAA0228Q019, FAA0228Q01F, FAA0228Q01J, FAA0228Q01L, FAA0228Q01R, FAA0228Q01S, FAA0228Q021, FAA0228Q022, FAA0228Q025, FAA0228Q027, FAA0228Q02A, FAA0228Q02B, FAA0228Q02C, FAA0228Q02E, FAA0228Q02M, FAA0228Q02N, FAA0229Q002, FAA0229Q003, FAA0229Q005, FAA0229Q009, FAA0229Q00A, FAA0229Q00E, FAA0229Q00H, FAA0229Q00Q, FAA0229Q00U, FAA0229Q00W, FAA0229Q014, FAA0229Q015, FAA0229Q01A, FAA0229Q01D, FAA0229Q01F, FAA0229Q01T, FAA0229Q01U, FAA0229Q01X, FAA0229Q01Y, FAA0229Q020, FAA0229Q02C, FAA0229Q02D, FAA0229Q02G, FAA0229Q02L, FAA0229Q02M, FAA0229Q02Q, FAA0229Q02R, FAA0229Q02S, FAA0229Q02Z, FAA0229Q032, FAA0229Q037, FAA0229Q03A, FAA0229Q03J, FAA0229Q03L, FAA0229Q048, FAA0229Q05X, FAA0229Q06K, FAA0229Q06Q, FAA0229Q06T, FAA0229Q06V, FAA0229Q06X, FAA0229Q071, FAA0229Q07A, FAA0229Q07N, FAA0229Q07Q, FAA0229Q07R, FAA0229Q07T, FAA0229Q07V, FAA0229Q07W, FAA0229Q086, FAA0229Q089, FAA0229Q08B, FAA0229Q08N, FAA0229Q08U, FAA0229Q08Y, FAA0229Q08Z, FAA0229Q090, FAA0229Q094, FAA0229Q095, FAA0229Q09D, FAA0229Q09E, FAA0229Q0AS, FAA0229Q0AT, FAA0229Q0C8, FAA0229Q0CB, FAA0229Q0CD, FAA0229Q0CK, FAA0229Q0CL, FAA0229Q0CM, FAA0229Q0CR, FAA0229Q0CT, FAA0229Q0CY, FAA0229Q0D0, FAA0229Q0D2, FAA0229Q0DB, FAA0229Q0DF, FAA0229Q0DK, FAA0229Q0DP, FAA0229Q0DQ, FAA0229Q0DS, FAA0229Q0EZ, FAA0229Q0F5, FAA0229Q0FJ, FAA0229Q0FS, FAA0229Q0FT, FAA0229Q0FY, FAA0229Q0GC, FAA0229Q0GE, FAA0229Q0GF, FAA0229Q0GK, FAA0229Q0GW, FAA0229Q0GZ, FAA0229Q0H1, FAA0229Q0H3, FAA0230Q004, FAA0230Q006, FAA0230Q007, FAA0230Q00C, FAA0230Q00J, FAA0230Q00T, FAA0230Q00V, FAA0230Q01F, FAA0230Q01N, FAA0230Q01T, FAA0230Q022, FAA0230Q025, FAA0230Q026, FAA0230Q02E, FAA0230Q02J, FAA0230Q02N, FAA0230Q02R, FAA0230Q02W, FAA0230Q03E, FAA0230Q03G, FAA0230Q03L, FAA0230Q03N, FAA0230Q03P, FAA0230Q041, FAA0230Q04C, FAA0230Q04N, FAA0230Q05C, FAA0230Q05Q, FAA0230Q05X, FAA0230Q05Y, FAA0230Q068, FAA0230Q06B, FAA0230Q06G, FAA0230Q06M, FAA0230Q06N, FAA0230Q06X, FAA0230Q06Y, FAA0230Q081, FAA0230Q082, FAA0230Q089, FAA0230Q090, FAA0230Q095, FAA0230Q09G, FAA0230Q09H, FAA0230Q09V, FAA0230Q09Z, FAA0230Q0A4, FAA0230Q0AD, FAA0230Q0AF, FAA0230Q0AL, FAA0230Q0AQ, FAA0230Q0AY, FAA0230Q0B0, FAA0230Q0B4, FAA0230Q0B9, FAA0230Q0BB, FAA0230Q0BE, FAA0230Q0BN, FAA0230Q0C5, FAA0230Q0CK, FAA0230Q0CL, FAA0230Q0CQ, FAA0230Q0D1, FAA0230Q0D4, FAA0230Q0D5, FAA0230Q0D6

Problem Description

Cisco UBR904-US and UBR904-RES shipped before August 24, 1998 may cause provisioning or network issues due to the same serial number or MAC address being assigned to multiple units.


A error during the manufacturing test process inadvertently created a situation where serial numbers printed on the bottom label of UBR904-US and UBR904-RES units may not match the serial number loaded into the Electronically Erasable Programmable Read Only Memory (EEPROM) of the units. In specific situations, this problem may result in duplicate MAC addresses being assigned to multiple units.

All serial numbers for UBR904-US and UBR904-RES units affected by this problem are listed at the end of this Field Notice.


Cisco is proactively contacting customers who have received suspect units prior to August 25, 1998 to arrange for replacements. If you have received a unit before August 25, 1998 and have not been contacted by Cisco, you can obtain a list of the affected serial numbers at the bottom of this field notice.

If you find a matching serial number(s), please copy the upgrade form below to an email message, fill it out, and email it to If you have any technical questions concerning the UBR904 product, please contact the Technical Assistance Center (TAC). If you have any questions about the replacement program, send email to

Upgrade Information

Customers who purchased the UBR904 can copy the upgrade form below to an email message, fill it out, and email it to to arrange for a replacement order.

Note:?Fields marked with an asterisk (*) are required fields.

Upgrade Form

Company Information
*ZIP/Postal Code
Contact Information
*First Name
*Last Name
*Phone (1) 
Fax (1) 
*Internet E-Mail: (Please use the following format:

Please provide a number that you can use when inquiring about order status.
*UBR904 Serial Numbers of Affected
*Number of Units (2)

For phone and fax, include 011 and the country code if you are outside of North America.

When entering more than one serial number in the serial number text entry field, be sure to type a comma between each serial number to separate them.

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: