Specifications

ISSU Introduction
86 New and Enhanced Features in AlliedWare Plus 5.4.4 Major and Minor Versions
For ISSU to progress, the above conditions must be met and there must be no pre-existing
ISSU operation in progress. If ISSU is unable to progress, a warning message will be printed
to the console. Similarly, when using VCStack Plus, if one of the chassis has only a single
CFC, the console will first display a warning message followed by a confirmation message.
The diagram of Figure 1 on page 86 illustrates ISSU’s automatic phase. This diagram
shows that the first step is to upgrade the software on the Member CFC. During this step
the line cards are still running the old software version from the existing Active CFC. Once
this step is complete, the Active CFC is deactivated and receives the software upgrade. At
this time the stack Active CFC role moves from the existing Active CFC to the Member CFC.
Once this process is complete the line cards can be manually upgraded.
Figure 1: Illustration Showing ISSU’s Automatic Phase
Old SW
Active CFC
Member CFC
Old SW
Line Card 1 Line Card 2
Old SW
Active CFC
New SW
Member CFC
Old SW
Line Card 1 Line Card 2
Member CFC
New SW
New SW
Active CFC
Old SW
Line Card 2
1. All cards running old
software version.
2. Reboot slave CFC with new
software version.
3. Do a failover and switch to
the new software version.
The CFC upgrades are now
complete.
Line Card 3 Line Card 4
Line Card 3 Line Card 4 Line Card 3 Line Card 4
Software
Version Messages
ISSU Overview - Automatic Phase
ISSU-Overview.eps
New SW
Software
Version Messages
Software
Version Messages
Software
Version Messages
Software
Version Messages
Line Card 1