The firmware package asr1000-rommon.173-1r.spa.pkg is the ROM Monitor (ROMMON) image for the Cisco ASR 1000 Series Aggregation Services Routers. It is specifically used to upgrade the low-level boot code on hardware components like Route Processors (RP), Embedded Services Processors (ESP), and line cards (SPA Interface Processors). Why You Need This Upgrade
Cisco Bug: CSCwa12192 - ASR1k 17.3(1r) ROMMON upgrade may cause module to go to "disabled" state. Cisco Bug: CSCwa12192. ASR1k 17. ASR1002-X Upgrade version path - Cisco Community
ROMMON is a specialized firmware that resides in the router’s read-only memory (ROM) and runs immediately upon power-up or reset. Its primary functions include: Hardware Diagnostics
| Platform | Applicable | Notes | |----------|------------|-------| | ASR 1001 | Yes | Integrated RP/ESP | | ASR 1001-X | Yes | Common bootflash issues resolved | | ASR 1002-X | Yes | Widely deployed – highly recommended upgrade | | ASR 1004 | Yes | Most benefits for dual-ESP setups | | ASR 1006 | Yes | Chassis with redundant RPs | | ASR 1013 | Yes | High-end chassis – critical for large bootflash | | ASR 1002-HX / 1006-HX | Partial | Newer generation uses different ROMMON branch, but this file works as fallback |
⚠️ Critical Constraint: Once upgraded to version 17.3(1r) on supported platforms, you cannot revert or downgrade to a ROMMON version earlier than 17.3(1r). ⚙️ How to Upgrade ROMMON


