Are you running Cisco Firepower Threat Defense (FTD) and having issues when you deploy your Device Platform settings? You are not alone, and no, you are not crazy! The platform settings can make the entire FTD box stop passing ALL traffic, even if it is configured correctly!! Yikes!!
Yes, there are some undocumented issues with the Cisco FTD platform settings, and it’s possible that you are experiencing issues that I have not seen and vice versa, but here is the most common problem I have:
First, the reason you need the platform setting on your FTD device is to configure items such as ICMP (see my ICMP blog), packet segmentation, NTP server, SNMP, Email and Syslog, SMTP, along with a few other things.
What I have found is difficult to diagnose. If your platform policy doesn’t work, your FMC will tell you nothing…no events, no alerts, nothing. It was pretty hard to find this issue…however, I did get the issue resolved after removing the Syslog external server settings and leaving the internal server settings and now traffic started flowing inside/outside again…that could be the issue or that could be just one issue at work here…not sure yet…
So, if your FTD box just stops working (stops passing all traffic!), and their are no events on the console or FMC, then remove your Platform policy from Devices>Platform Settings, redeploy and that should solve your issue…