topic Re: Adding Network DNS Server to Data Interface in Network Security

Adding Network DNS Server to Data Interface

ATCUSN — Mon, 24 May 2021 16:34:40 GMT

The Firepower FDM DNS server settings only allow for one Data Interface and one Management Interface. My firepower will be connected to two separate LANs with separate domain controllers on separate data interfaces.

How does the system know which network DNS server to use?

Do I add both network DNS server IP addresses to the Data Interface?

Re: Adding Network DNS Server to Data Interface

nspasov — Mon, 24 May 2021 17:28:41 GMT

It really depends on what your environment looks like and what you are trying to accomplish. You can always use the out-of-band management interface as long as it can route to both DNS servers.

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Re: Adding Network DNS Server to Data Interface

ATCUSN — Mon, 24 May 2021 18:10:01 GMT

The firepower was not resolving the DC’s host name. I'm not having trouble accessing the FDM from any interface.

I had to create a new DNS Group that included the DC’s IP in addition to the Cisco Umbrella DNS servers.

Once the Firepower is connected to the production LAN I will have to add another network DNS server to the group. This is not ideal.

What I was trying to accomplish is to create one DNS group for inside interface A and another DNS Group for inside interface B.