The other day while I was playing with my FTD lab I came across a very strange issue. Basically the FMC was failing deploying the policies to one of the FTD appliances. The error message was saying FTD exist with same serial number. In my lab I had a couple of FTDv, and there was no fancy configuration yet or anything weird.
Looking around on the internet, it ended up being an issue that a few people experienced as well. This issue seems to happen only when you deploy additional FTD appliances to your deployment. So, it seems to happen only at the deployment stage, way before you start setting up your deployment.
I am not a 100% sure if this FTD exist with same serial number issue happens only with the virtual FTD appliances or with the physical ones as well. But my gut feeling is that it seems to be related to the virtual appliances only. The reason why I am thinking this is because the virtual appliances comparing to the physical ones they don’t come with any pre-set serial number. However, the physical ones they go out of the factory with their serial numbers built in. I believe this is caused by a software bug, but not sure.
How I could fix that issue?! well, because as I said it happened at the very early stage of my deployment, I had just removed and re-added the FTD applianc that was showing in the error message. After a few minutes the error was gone. Here is the error I was getting:
Thank you for reading!
