Table 4. Feature History
Feature Name
|
Release Information
|
Description
|
Secondary ROMMON Partition Auto Upgrade
|
Cisco IOS XE Bengaluru 17.4.1 |
This feature supports secondary ROMMON partition auto upgrade after a successful primary ROMMON partition is complete for
NCS 4216 routers.
|
Secondary ROMMON Version Auto Upgrade
|
Cisco IOS XE Bengaluru 17.5.1 |
After primary ROMMON version is auto upgraded, secondary ROMMON version auto upgrade process takes place. The secondary ROMMON
upgrade is only completed during the next planned manual reload of the router. This is applicable to NCS 4201/4202 routers.
|
Starting with Cisco IOS XE Bengaluru release, 17.6.1, the 15.6(49r)S ROMMON version filters the restricted ROMMON variables
during the bootup.
Starting with Cisco IOS XE Bengaluru release, 17.5.1, secondary ROMMON partition is also auto upgraded after a successful
primary ROMMON partition upgrade is complete. You can reload the router at the next planned reload to complete the secondary
ROMMON upgrade.

Note
|
If the secondary ROMMON version is lesser than that of the primary ROMMON version, the secondary ROMMON gets auto upgraded.
|
For Cisco IOS XE Amsterdam Release 17.3.x, Cisco IOS XE Bengaluru Release 17.4.x, and earlier, the secondary ROMMON partition
is not auto upgraded. You must manually upgrade it using the upgrade rom-mon filename command.
Starting with ROMMON release version 15.6(43r)S, ROMMON version is secure. Once the ROMMON version is upgraded, it cannot
be downgraded to a non-secure ROMMON version.
Secure ROMMON is supported from Cisco IOS XE Amsterdam Release 17.3.1 onwards. However, it is compatible with all the releases.
Any future secure ROMMON upgrade or downgrade is only possible from Cisco IOS XE Amsterdam Release 17.3.1 onwards.
Any non-secure FPGA bundled releases moving to Cisco IOS XE Bengaluru Release 17.3.x or future releases can result in an FPGA
upgrade and a ROMMON upgrade. If FPGA upgrade happens parallely with the ROMMON upgrade, you can only expect a single reload.
If FPGA upgrade gets delayed and happens post ROMMON upgrade, two reloads are expected to complete both the upgrade processes.
This is followed by a successful bootup of the target release image.
The router has two ROMMON regions (ROM0 and ROM1). We recommend that the upgrade is performed on both the regions.

Note
|
For Cisco IOS XE Gibraltar Release 16.9.5, Cisco IOS XE Gibraltar Release 16.12.3, Cisco IOS XE Amsterdam 17.1.x, and Cisco
IOS XE Amsterdam 17.3.1, a minimum diskspace of 2 MB is required in the boot flash memory file system for a successful ROMMON
auto upgrade process. For a diskspace lesser than 2 MB, ROMMON auto upgrade fails and the router reboots.
|

Note
|
Routers running a ROMMON version that is lower than version 15.6(33r)S is auto upgraded to version 15.6(33r)S during a router
restart. However, if a Cisco IOS XE release with ROMMON image is bundled with a version lower than the running ROMMON version,
then the ROMMON is not auto downgraded.
|

Note
|
Before installing the Cisco IOS XE Amsterdam 17.3.1, you must upgrade the ROMMON to version 15_6_43r_s or higher to avoid bootup failure. This is applicable to NCS 4202 routers.
|

Note
|
Starting with Cisco IOS XE Amsterdam 17.3.1, While performing an auto upgrade of ROMMON, only primary partition is upgraded.
Use the upgrade rom-mon filename command to upgrade the secondary partition of the ROMMON. However, the router can be reloaded during the next planned reload
to complete the secondary ROMMON upgrade.
|

Caution
|
To avoid actions that might make your system unable to boot, read this entire section before starting the upgrade.
|