ids – Replaying PCAPs to test firewall

I am working on a personal project using a custom IDS together with PfSense firewall. There are a few online datasets containing pcap files of benign and attack traffic, my goal would be to replay these pcaps to the firewall so that I can then analyze its response.

I have tried replaying using tcpreplay as it is but it did not work, I have the feeling some addresses need to be changed in order to replay within my network.

Could someone advise me on how I can do this?