Determining the upgrade procedure
Use Table 13 to choose an upgrade command set, depending on the ISSU method.
Identify the hardware redundancy condition.
ISSU can maintain service continuity only when the IRF fabric has multiple members and uses the ring topology.
IMPORTANT:
If hardware redundancy is not available, service discontinuity is not avoidable. Make sure you understand the impact of the upgrade on the network.
Choose the correct procedure from the procedures described in "Performing an ISSU by using issu commands" or "Performing an ISSU by using install commands."