DAD configuration considerations
Note the following general considerations when using DAD:
- The DAD process is disruptive to traffic.
- Currently, only DHCPv4 is supported.
- Configuration download is not supported during a firmware downgrade.
- Configurations are not downloaded if the DAD process is aborted due to a sanity check failure, or if you are downloading the same firmware version.
- If an existing firmware download session is either occurring or paused, such as during a firmware commit, DAD is not triggered. Instead, the last firmware download session continues. If a firmware download is in progress and you attempt to enable DAD, you are prompted to try again later.
- In-Service Software Upgrade (ISSU) is not supported at this time.
- For dual management module (MM) chassis (VDX 8770 chassis), the dual MM must be in sync from the chassis bootup (not from HA failover). In a chassis system, both MMs are rebooted at the same time.
- DAD is not supported in FIPS mode.
- You can choose to apply either the default configuration or the preset configuration.
- DAD must be enabled on the principal node first. All the other nodes must be enabled in parallel.
- The preset configuration can be either a configuration file or a running setup script.
- Cluster principal node failover is not supported.
- Adding a node into an existing cluster is not supported.
- DAD over in-band is not supported.
- Virtual Fabrics is not supported with DAD. You must disable Virtual Fabrics before starting the DAD process in the global configuration file or in the script.
- If switches are already configured with virtual fabric, this configuration will not be changed by the DAD process. Similarly, other global configurations that are not modified by the copy default to startup command will not be modified by DAD either.