In-Service Software Upgrade (ISSU) Matrix for Catalyst 9k devices

Term	Meaning
ISSU	In-Service Software Upgrade
EM	Extended Maintenance release
SM	Standard Maintenance release
LDPE	Licensed Data Payload Encryption
NPE	No Payload Encryption
CLI	Command-Line Interface
SNMP	Simple Network Management Protocol
SVL	StackWise Virtual or StackWise Virtual Link
SUP	Supervisor engine or supervisor module
QuadSup	Quad Supervisor configuration
9k	Shorthand for the Catalyst 9000 family
CSC…	Cisco Bug Search identifier
N	Starting EM train in the compatibility calculation
N+1	Next eligible EM train
N+2	Second eligible EM train after the starting train

ISSU Release Lookup

Use this matrix to determine the supported ISSU paths for Catalyst 9400, 9400X, 9500, 9500H, 9500X, 9600, 9600X Series Switches.For releases earlier than 17.x, refer to In-Service Software Upgrade (ISSU).

Device

Release

Upgrade from

Upgrade to

Supported Platforms and Recommended Releases for ISSUValidate the platform baseline before checking the release path.

Platforms	ISSU Starting Release	ISSU Recommended Starting Release
C9400 (4,7,10 slots-dual supervisor single chassis)	16.9.1	16.9.3
C9400 (SVL 10-slot)	16.12.1c	16.12.2
C9400 (SVL 4,7 slots)	16.9.2	16.9.3
C9400X (4,7,10 slots-dual supervisor single chassis)	17.9.1	17.9.1
C9400X (SVL)	17.9.1	17.9.1
C9500 (SVL)	16.9.2	16.9.3
C9500 High Performance (SVL)	16.12.1c	16.12.2
C9500X (SVL)	17.12.1	17.12.2
C9600 (Dual supervisor)	16.12.1	16.12.2
C9600 (Quad supervisor)	17.3.2a	17.3.2a
C9600 (SVL)	16.12.1	16.12.2
C9600X (Dual supervisor)	17.9.1	17.9.2
C9600X (Quad supervisor)	17.9.2	17.9.2
C9600X (SVL)	17.12.1	17.12.2

26.2.1 ISSU-compatible platforms

Platform	Release	Supported ISSU from
C9500 High Performance SVL	26.2.1	26.1.1, 26.1.2
C9500X SVL	26.2.1	26.1.1, 26.1.2
C9400X-SUP-2/C9400X-SUP-2XL SVL	26.2.1	26.1.1, 26.1.2
C9600-SUP-1 Dual Sup and SVL	26.2.1	26.1.1, 26.1.2
C9600X-SUP-2 Dual Sup	26.2.1	26.1.1, 26.1.2

Rules and RestrictionsUse these rules to determine whether an ISSU path is supported.

Compatibility	Rule or Restriction	Example
Supported	EM to EM within the same major release train is limited to N, N+1, and N+2, where N is the starting EM	17.3.x → 17.3.x, 17.6.x, or 17.9.x
Supported	All rebuilds within the same EM release	17.3.1 → 17.3.2, 17.3.3, 17.3.4 and later.
Supported	Target EM release date must be after the source EM release date	—
Supported	As an additional exception, different source and target releases may share the same release date when the target train is the same train, N+1, or N+2	17.12.8 → 17.15.6
Unsupported	EM of a release train to EM of another major release train	17.x → 26.x
Unsupported	SM to EM, EM to SM, engineering special, s, or similar images	17.4.x → 17.6.x or 17.6.x → 17.8.x
Unsupported	ISSU between LDPE and NPE images	—
Unsupported	Downgrades	—

Known Upgrade BlockersReview the documented impact and required action before starting an affected ISSU path.

Impacted Platform	ISSU PathKnown upgrade blocker. Affected target releases are marked with the warning symbol.	Impact	Details	Bug ID
Catalyst 9600 with Quad Supervisor Module Configuration and with StackWise Virtual (C9600-SUP-1)	All ISSU paths when timezone configuration is present	ISSU and install operations may fail.	Remove the timezone configuration before starting the operation. After the operation completes, reconfigure the timezone setting.	CSCwv75543
Catalyst 9600X with Quad Supervisor Module Configuration (C9600X-SUP-2)	All ISSU paths when timezone configuration is present	ISSU and install operations may fail.	Remove the timezone configuration before starting the operation. After the operation completes, reconfigure the timezone setting.	CSCwv75543
Catalyst 9400 with Dual Supervisor Module Configuration	17.12.x → 17.15.1/17.15.2	ISSU might fail.	Remove unsupported CLI before ISSU, including `snmp enable traps energywise` and `snmp-server enable traps license`.	CSCwn57884
Catalyst 9400 with StackWise Virtual	17.12.x → 17.15.1/17.15.2	ISSU might fail.	Remove unsupported CLI before ISSU, including `snmp enable traps energywise` and `snmp-server enable traps license`.	CSCwn57884
Catalyst 9400X with Dual Supervisor Module Configuration	17.12.x → 17.15.1/17.15.2	ISSU might fail.	Remove unsupported CLI before ISSU, including `snmp enable traps energywise` and `snmp-server enable traps license`.	CSCwn57884
Catalyst 9400X with StackWise Virtual	17.12.x → 17.15.1/17.15.2	ISSU might fail.	Remove unsupported CLI before ISSU, including `snmp enable traps energywise` and `snmp-server enable traps license`.	CSCwn57884
Catalyst 9500 with StackWise Virtual	17.12.x → 17.15.1/17.15.2	ISSU might fail.	Remove unsupported CLI before ISSU, including `snmp enable traps energywise` and `snmp-server enable traps license`.	CSCwn57884
Catalyst 9500 High Performance with StackWise Virtual	17.12.x → 17.15.1/17.15.2	ISSU might fail.	Remove unsupported CLI before ISSU, including `snmp enable traps energywise` and `snmp-server enable traps license`.	CSCwn57884
Catalyst 9500X with StackWise Virtual	17.12.x → 17.15.1/17.15.2	ISSU might fail.	Remove unsupported CLI before ISSU, including `snmp enable traps energywise` and `snmp-server enable traps license`.	CSCwn57884
Catalyst 9600 with Dual Supervisor Module Configuration	17.12.x → 17.15.1/17.15.2	ISSU might fail.	Remove unsupported CLI before ISSU, including `snmp enable traps energywise` and `snmp-server enable traps license`.	CSCwn57884
Catalyst 9600 with Quad Supervisor Module Configuration and with StackWise Virtual	17.12.x → 17.15.1/17.15.2	ISSU might fail.	Remove unsupported CLI before ISSU, including `snmp enable traps energywise` and `snmp-server enable traps license`.	CSCwn57884
Catalyst 9600X with Dual Supervisor Module Configuration	17.12.x → 17.15.1/17.15.2	ISSU might fail.	Remove unsupported CLI before ISSU, including `snmp enable traps energywise` and `snmp-server enable traps license`.	CSCwn57884
Catalyst 9500 with StackWise Virtual	Any successful In-Service Software Upgrade with breakout configuration	Breakout configuration may be removed.	This is a post-upgrade configuration risk for C9500 StackWise Virtual.	—
Catalyst 9600 with Dual Supervisor Module Configuration	17.3.1/17.3.2a/17.3.3/17.3.4 → 17.6.x17.3.1/17.3.2a/17.3.3/17.3.4 → 17.9.1	Direct ISSU path has a documented failure risk.	Upgrade to 17.3.5 first, then perform ISSU to the final target release. In-Service Software Upgrade to 17.9.1 might fail.	CSCwc54402
Catalyst 9600 with Quad Supervisor Module Configuration and with StackWise Virtual	17.6.4 → 17.9.3	ISSU might fail.	This QuadSup path has a documented failure risk.	CSCwc54402
Catalyst 9600X with StackWise Virtual	17.12.x → 17.15.x/17.18.x17.15.1 → 17.15.x/17.18.x17.15.x → 17.18.1	ISSU is not supported.	These StackWise Virtual paths are not supported.	CSCwm88713
Catalyst 9500X with StackWise Virtual	17.12.x → 17.15.x/17.18.x17.15.1 → 17.15.x/17.18.x17.15.x → 17.18.1	ISSU is not supported.	These StackWise Virtual paths are not supported.	CSCwm88713
Catalyst 9600X with StackWise Virtual	17.18.1 → 17.18.x	ISSU is not supported.	These StackWise Virtual paths are not supported.	CSCwr96718
Catalyst 9600X with Quad Supervisor Module Configuration	17.18.1 → 17.18.x	ISSU is not supported.	These StackWise Virtual paths are not supported.	CSCwr96718
Catalyst 9500X with StackWise Virtual	17.18.1 → 17.18.x	ISSU is not supported.	These StackWise Virtual paths are not supported.	CSCwr96718

Detailed ISSU Release Matrix

Hover over, focus, or select a matrix cell to inspect its upgrade path.

Loading release matrix…

Symbol	Status	Meaning
Y	Supported	The target is a different release whose date is later than or equal to the source date and whose train is the same train (`N`), next train (`N+1`), or second-next train (`N+2`).
N	Not supported	The target release date is older than the source date, the target train is behind the source train, or the target train is beyond `N+2`.
⚠ N	Known upgrade blocker	The path meets the standard release-policy rules but is treated as unsupported because a known upgrade blocker applies. Select or hover over the warning icon to review the associated Bug ID.
—	Same release	The source and target are the same release; therefore, this is not an upgrade path.

Document	Document Title
Software Configuration Guides	Software Configuration Guides (Catalyst 9400 Switches) Software Configuration Guides (Catalyst 9500 Switches) Software Configuration Guides (Catalyst 9600 Switches)
Release Notes	Release Notes (Catalyst 9400 Series Switches) Release Notes (Catalyst 9500 Series Switches) Release Notes (Catalyst 9600 Series Switches)
Command References	Command References (Catalyst 9400 Series Switches) Command References (Catalyst 9500 Series Switches) Command References (Catalyst 9600 Series Switches)
Troubleshooting TechNote	In-Service Software Upgrade (ISSU) on Catalyst 9000 Series Switches

Acronyms and abbreviations

ISSU Release Lookup

Upgrade from

Upgrade to

26.2.1 ISSU-compatible platforms

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