FMC NAT to Outside

Lee Dress — Wed, 26 Jan 2022 15:14:22 GMT

I have created a rule to NAT my FMC to my outside interface to allow me to add remote FTD devices to FMC.

I have an access control policy that allows TCP/8305.

I need to test this to see if it will work before I prep my remote FTD device.

I have tried Telneting to port 8305 from outside and get no response.

the problem is, when I try it from the same subnet the FMC is on, I get the same result.

how can I verify that FMC is listening on tcp/8305?

I'm pretty sure my rules are correct, but if I get no response from the internal subnet, I have no way of knowing.

Re: FMC NAT to Outside

Udupi Krishna. — Thu, 27 Jan 2022 03:23:35 GMT

The easiest way to verify if 8305 is listening, run "netstat -an | grep 8305" via expert mode. If it's in listening state, run tcpdump on the FMC while filtering port 8305, initiate traffic locally.

This guide should get you started - https://www.cisco.com/c/en/us/support/docs/security/firepower-ngfw/215540-configure-verify-and-troubleshoot-firep.html

topic Re: FMC NAT to Outside in Network Security

FMC NAT to Outside

Re: FMC NAT to Outside