Identifying the ISSU method
Execute the display version comp-matrix file command for the upgrade image version.
Check the Version compatibility list field.
If the running software version is in the list, a compatible upgrade is required.
If the running software version is not in the list, an incompatible upgrade is required.
Identify the ISSU method:
If a compatible upgrade is required, check the Upgrade Way field to identify the ISSU method. For more information about ISSU methods, see Table 12.
If an incompatible upgrade is required, check the end of command output for the Incompatible upgrade string.