About the upgrade sequence
If you are planning to upgrade both Core and Edge as part of the same procedure, then the normal sequence is to upgrade the Core appliances and then upgrade the Edges.
If you are only upgrading Core or Edge, but not both, this section does not apply.
If there is HA at the Edge and no HA at the Core, the sequence is still the same—Core first followed by Edge with the standby Edges preceding active Edge upgrades.
The following table summarizes the sequence.
| Upgrade phase |
|---|
Deployment | First | Second |
|---|
Core - Edge | Core | All Edges owned by the Core. |
Core HA - Edge | Core HA | All Edges owned by the Core HA. |
Core - Edge HA | Core | All Edgees are owned by the Core. Upgrade the standby Edge first, and wait for it to be synchronized with the active Edge. Next, upgrade the active Edge. |
Core HA - Edge HA | Core HA | All Edges are owned by the Core HA. Upgrade standby Edges before upgrading active Edges. |
If you have an HA deployment, it is possible to have mixed software versions between HA peers for a short period of time. You can also run with mismatched software versions between Core and Edge for short periods of time; however, we do not recommend this practice.
In Core and Edge 4.2 and later, there are restrictions in place to enforce supported upgrade and downgrade paths. You can upgrade or downgrade the Core or Edge software up to a maximum of two versions beyond the current version.
If you attempt to upgrade or downgrade to an unsupported version, a warning opens and the upgrade or downgrade does not proceed.
If there are any doubts about any of these procedures, contact Riverbed Support.