Asr1000-rommon.173-1r.spa.pkg -

Before upgrading, check your current ROMMON version:

Router# show platform

Look for the output under the Route Processor (R0). It should list the ROMMON version.

asr1000-rommon.173-1r.spa.pkg is a small but mighty firmware package that enables modern IOS-XE releases on ASR 1000 RP2 platforms. It is not a routine upgrade, but a foundational step when moving to IOS-XE 17.3 or higher, adding hardware support, or patching critical boot-time vulnerabilities. Treat it with respect: test on a redundant RP, never interrupt the process, and always verify the new version after reload.

For most production networks, this file sits quietly on flash, loaded once during a major lifecycle upgrade—and if all goes well, you will never need to interact with the rommon > prompt it helps protect.

Here’s a concise, engaging blog post outline and draft based on the filename asr1000-rommon.173-1r.spa.pkg – aimed at network engineers and Cisco ASR1000 administrators.

ROMMON (ROM Monitor) is the bootstrap firmware embedded on the motherboard of Cisco routers and switches. When you power on an ASR1000, the CPU has no memory, no routing protocols, and no interfaces active. The first code to execute resides in a small ROM chip. That code is ROMMON. asr1000-rommon.173-1r.spa.pkg

Think of it as the BIOS/UEFI of a PC. Its primary responsibilities are:

Without a valid ROMMON, your ASR1000 is a very expensive paperweight.

Q: Does asr1000-rommon.173-1r.spa.pkg work on the ASR1001 (non-X)?
A: Yes, the ASR1001 (original) uses the same ROMMON binaries. However, older ASR1001 (with 2GB DRAM) may not support the full 17.x ROMMON. Always verify hardware compatibility with Cisco.

Q: Does upgrading ROMMON erase my configuration?
A: No. The running-config and startup-config are stored in a separate partition (NVRAM or bootflash variable). ROMMON upgrade is non-destructive to configurations.

Q: Can I use this file as a boot image?
A: No. You cannot boot IOS-XE from a ROMMON .pkg file. You must still specify an IOS-XE .bin or packages.conf in BOOT variable. The ROMMON only loads that. Before upgrading, check your current ROMMON version: Router#

Q: My router says "ROMMON upgrade not supported" – why?
A: Some ASR1000 variants, especially older RP1 sub-modules, have soldered, non-upgradable ROMMON. In that case, you are stuck with an older version.

In the world of enterprise and service provider networking, the Cisco ASR 1000 series stands as a workhorse for aggregation, WAN edge, and broadband access. While network engineers spend most of their time worrying about IOS XE versions, feature sets, and license levels, there is one tiny, often overlooked file that holds the power to resurrect a bricked router: asr1000-rommon.173-1r.spa.pkg.

This seemingly cryptic filename is the ROMMON (ROM Monitor) firmware upgrade package for the ASR 1000 series. If your ASR 1002, 1004, or 1006 router suffers a corrupted bootflash, a failed field-replaceable unit (FRU), or a catastrophic IOS crash, the ROMMON is the first code that executes. Without the correct, updated ROMMON, your router might fail to boot or, worse, fail to recover via USB or TFTP.

This article provides an exhaustive breakdown of this file—what it is, why version 173-1r matters, how to upgrade it safely, and how to troubleshoot when things go wrong.

A standard reload may not be enough. On most ASR1000 chassis: Look for the output under the Route Processor (R0)

reload location all force-download

Or power cycle the chassis entirely (turn off/on). The ROMMON version is read very early in POST.

Your organization likely has a disaster recovery plan for servers, storage, and applications. Do you have one for the router’s bootstrap firmware? The file asr1000-rommon.173-1r.spa.pkg should be stored offline, alongside:

Test your ROMMON recovery every 12 months. Boot from USB, run dir, load a minimal IOS XE. That drill will expose any bootflash degradation or ROMMON bugs before an emergency.

Many network breaches target firmware before the OS loads. The NSA and CERT have published alerts regarding ROMMON rootkits (e.g., "JCR" or "Lurid" attacks). By staying at 173-1r, you benefit from:

If your compliance requires NIST SP 800-124 (firmware integrity), 173-1r meets the baseline.