FTD Lost LAN connection after upgraded to 7.2.5

[alexseo]

We have experienced an issue with FTD after upgrading the software to version 7.2.5. We have experienced the same issues on multiple FTD devices from different branch offices recently. It works fine most of the time. But it will suddenly lose connection to LAN which results in affecting the user's internet connection. Sometimes rebooting the firewall will resolve the issue, but sometimes it won't.

While having the problem, we can manage the FTD via FDM from the WAN interface. The FTD shows that the LAN connection is connected. However, we cannot connect to any LAN device from the firewall. All users are unable to connect to the internet and cannot find the root cause/related bugs. 

Please kindly advise. 

*Model: Cisco Firepower 1010 Threat Defense

*Current Version: FTD 7.2.5-208

[MHM Cisco World]

In SW connect to one FTD face problem 

Do

Show mac address 

Show cdp neighbor 

Show interface status 

Show interface x/x

In FTD 

Show interface x/x 

Show route 

Share above 

MHM

[alexseo]

Thank you for the reply. 

Recently, I upgraded it to v7.2.5.1 to fix the security vulnerability but it happened again. In order to solve this quickly, I had to roll back to the previous version 7.0.4, and it is running normally now. 

I did do it after 7.0.4 as no way to access the switch if the firewall does not work. Please find the attachment for your reference. 

Thank you in advance. 

[alexseo · Accepted solution]

It is because of a bug after confirming with the Cisco TAC. It needs to be upgraded to 7.2.6 when released.