FN-2019-429 - VDX6940-36Q, -24Q New Hardware not compatible with older NOS versions

VDX 6940-36Q and VDX 6940-24Q with a newer hardware component require a NOS version where the fixes exist. Networks that are not upgraded to these later NOS releases will not be able to install a VDX6940 that is newly purchased or received as an RMA replacement.

VDX 6940-36Q and VDX 6940-24Q with the new hardware component require a NOS version with the code fixes for defect IDs 660022 and 660018.

This issue is only applicable to VDX 6940-36Q and VDX 6940-24Q with newer hardware components when used with NOS versions that do not include the NOS fix. System performance of the VDX 6940-36Q and VDX 6940-24Q can get degraded and experience an unexpected reload and may go into a state where ‘netinstall’ is required to recover the device.

VDX 6940-36Q & VDX 6940-24Q (with newer hardware component as described in the Symptoms section.)

NOS 6.0.2g, NOS 7.0.2, NOS 7.1.0a, NOS 7.2.0a and earlier versions

To identify a newer hardware component, execute show chassis CLI and verify Factory Part Num. If the last 2 digits are 11 or higher, it is running with the affected hardware component as below.
 

sw0# show chassis
…
Factory Part Num: 40-1001012-11

VDX6940-36Q and VDX 6940-24Q with a newer hardware component will ship with a compatible NOS version from manufacturing and firmware downgrade and upgrade cases have been handled as below:  

1. Firmware download to a NOS version without the uboot changes [Ex: NOS7.0.1c] will NOT be supported and will be blocked:

sw0# firmware download [default-config] scp user <UN> password <PW> host 10.10.10.10 directory <ImageDir>/nos7.0.1c  

Performing system sanity check...  

A newer hardware component has been detected, thus firmware download is blocked
to avoid degrading the system performance of the VDX 6940-36Q platform.  
The preinstall script failed.  
sw0# 

2. Firmware download to a NOS version with the uboot changes [Ex: NOS7.2.0b] will be supported.  

sw0# firmware download [default-config] scp user <UN> password <PW> host 10.10.10.10 directory <ImgaeDir>/nos7.2.0b/  

Performing system sanity check...  

This command will cause a cold/disruptive reboot and will require that
existing telnet, secure telnet or SSH sessions be restarted.
© 2016 Brocade Communications Systems, Inc. All Rights Reserved. TSB 2017-260-A 3 of 3  

Do you want to continue? [y/n]:  

3. Firmware Upgrade/Downgrade when a cluster has a variety of products including affected products with a newer hardware component.  

If planning to perform a cluster wide firmware download operation, then it would be best to identify the vulnerability with this issue on any affected product by verifying the “Factory Part Num” as mentioned above prior to the upgrade.  This is to ensure avoiding a partial cluster upgrade with the other half blocked on older releases due to other nodes in the cluster failing upgrade due to the presence of the issue on any single applicable node. If any node has the newer component, we recommend upgrading the entire cluster to one of the NOS releases with the uboot changes.

Please do not use the “firmware install” CLI for NOS version upgrade or downgrade on VDX 6940-36Q or VDX 6940-24Q with a newer hardware component, as it will not block firmware download to NOS version which does not have the required NOS changes.

In order to install either new or RMA replacements of VDX6940s into an existing network, the minimum versions of NOS 6.0.2h, NOS 7.0.2a, NOS 7.1.0b, NOS 7.2.0b, NOS 7.3.0 and later versions are required.