Revert Threat Defense
About Reverting FTD
Reverting FTD returns the software to its state just before the last major or maintenance upgrade. Reverting after patching necessarily removes patches as well. You must enable revert when you upgrade the device, so the system can save a revert snapshot.
Reverted Configurations
Configurations that are reverted include:
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Snort version.
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Device-specific configurations.
General device settings, routing, interfaces, inline sets, DHCP, SNMP — anything you configure on the
page. - Objects used by your device-specific configurations.
These include access list, AS path, key chain, interface, network, port, route map, and SLA monitor objects. If you edited these objects after you upgraded the device, the system creates new objects or configure object overrides for the reverted device to use. This allows your other devices to continue handling traffic according to their current configuration.
After a successful revert, we recommend you examine the objects used by the reverted device and make any necessary adjustments.
Configurations Not Reverted
Configurations that are not reverted include:
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Shared policies that can be used by multiple devices; for example, platform settings or access control policies.
A successfully reverted device is marked out-of-date and you should redeploy configurations.
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For the Firepower 4100/9300, interface changes made using the Firepower Chassis Manager or the FXOS CLI.
Sync interface changes after a successful revert.
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For the Firepower 4100/9300, FXOS and firmware.
If you are required to run the recommended combination of FXOS and FTD, you may need a full reimage; see Guidelines for Reverting FTD.
Guidelines for Reverting FTD
System Requirements
Revert is supported for major and maintenance upgrades to FTD Version 7.1+.
Revert is not supported for:
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Upgrades to earlier versions.
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Patches and hotfixes.
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Container instances.
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FMC upgrades.
Reverting High Availability or Clustered Devices
When you use the FMC web interface to revert FTD, you cannot select individual high availability units or clustered nodes. The system automatically reverts them simultaneously. This means that interruptions to traffic flow and inspection during revert depend on interface configurations only, as if every device were standalone.
Note that revert is supported for fully and partially upgraded groups. In the case of a partially upgraded group, the system removes the upgrade from the upgraded units/nodes only. Revert will not break high availability or clusters, but you can break a group and revert its newly standalone devices.
Revert Does Not Downgrade FXOS
For the Firepower 4100/9300, major FTD versions have a specially qualified and recommended companion FXOS version. After you return to the earlier version of FTD, you may be running a non-recommended version of FXOS (too new).
Although newer versions of FXOS are backwards compatible with older FTD versions, we do perform enhanced testing for the recommended combinations. You cannot manually downgrade FXOS, so if you find yourself in this situation and you want to run a recommended combination, you will need a full reimage.
Scenarios Preventing Revert
If you attempt to revert in any of these situations, the system displays an error.
Scenario |
Solution |
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Communications between the FMC and device are disrupted. |
You must use the FMC to revert FTD. You cannot use the device CLI. |
Revert snapshot is not available because:
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None. If you think you might need to revert after a successful upgrade, use System () to upgrade FTD. This is the only way to set the Enable revert after successful upgrade option, and is in contrast to our usual recommendation to use the threat defense upgrade wizard. The revert snapshot is saved on the FMC and the device for thirty days, after which it is automatically deleted and you can no longer revert. You can manually delete the snapshot from either appliance to save disk space, but this removes your ability to revert. |
Last upgrade failed. |
Return the device to its pre-upgrade state by canceling the upgrade. Or, fix the issues and try again. Revert is for situations where the upgrade succeeds, but the upgraded system does not function to your expectations. Reverting is not the same as canceling a failed or in-progress upgrade. If you cannot revert or cancel, you will have to reimage. |
Management access interface changed since the upgrade. |
Switch it back and try again. |
Clusters where the units were upgraded from different versions. |
Remove units until all match, reconcile cluster members, then revert the smaller cluster. You may also be able to revert the newly standalone units. |
Clusters where one or more units were added to the cluster after upgrade. |
Remove the new units, reconcile cluster members, then revert the smaller cluster. You may also be able to revert the newly standalone units. |
Clusters where the FMC and FXOS identify a different number of cluster units. |
Reconcile cluster members and try again, although you may not be able to revert all units. |
Revert FTD with FMC
You must use the FMC to revert FTD. You cannot use the device CLI.
Threat Defense History:
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7.1: Initial support.
Before you begin
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Make sure revert is supported. Read and understand the guidelines.
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Back up to a secure external location. A failed revert may require a reimage, which returns most settings to factory defaults.
Procedure
Step 1 |
Choose . |
Step 2 |
Next to the device you want to revert, click More () and select Revert Upgrade. |
Step 3 |
Confirm that you want to revert and reboot. |
Step 4 |
Monitor revert progress. In high availability/scalability deployments, traffic flow and inspection resume when the first unit comes back online. If the system shows no progress for several minutes or indicates that the revert has failed, contact Cisco TAC. |
Step 5 |
Verify revert success. After the revert completes, choose and confirm that the devices you reverted have the correct software version. |
Step 6 |
(Firepower 4100/9300) Sync any interface changes you made to FTD logical devices using the Firepower Chassis Manager or the FXOS CLI. On the FMC, choose , edit the device, and click Sync. |
Step 7 |
Complete any other necessary post-revert configuration changes. For example, if you edited objects used by device-specific configurations after you upgraded the device, the system creates new objects or configures object overrides for the reverted device to use. We recommend you examine the objects used by the reverted device and make any necessary adjustments. |
Step 8 |
Redeploy configurations to the devices you just reverted. A successfully reverted device is marked out-of-date. Because the device will be running an older version, newer configurations may not be supported even after a successful deploy. |