ISSU System Requirements
You can use ISSU to upgrade from an ISSU-capable software release to a newer software release.
To perform an ISSU, your device must be running a Junos OS release that supports ISSU for the specific platform. See Table 1 for platform support.
Table 1 lists the platforms on which an ISSU can be performed.
Table 1: Low-Impact ISSU Platform Support
Device | Junos OS Release |
|---|---|
SRX5800 | 10.4R4 or later |
SRX5600 | 10.4R4 or later |
SRX5400 | 12.1X46-D20 or later |
SRX3600 | 10.4R4 or later |
SRX3400 | 10.4R4 or later |
SRX1400 | 10.4R4 or later |
 | Note: For ISSU support on SRX Series devices and limitations, see ISSU upgrade limitations on SRX High End Firewalls. |
Note the following limitations related to an ISSU:
- The ISSU process is aborted if the Junos OS version specified for installation is a version earlier than the one currently running on the device.
- The ISSU process is aborted if the specified upgrade conflicts with the current configuration, the components supported, and so forth.
- ISSU does not support the extension application packages developed using the Junos OS SDK.
| Note: To downgrade from an ISSU-capable release to a previous software release (ISSU-capable or not), use the request system software add command. Unlike an upgrade using the ISSU process, a downgrade using the request system software add command might cause network disruptions and loss of data. |
