Best redirect method for IDS


I'd like to install an IDS system. Like such a system needs more resources, i want to pass all my data to a server in my net.
I have 2 openwrt routers in mesh, ohne has an USB-LTE stick for internet.
I have seen different posibilities, sniffer mode, iptable redirects, and i thing changing default gateway could also be an option, but advantages and disadvantages are not clear and i have no idea which method is the best for me.
How do i have to configure openwrt to pass at least all packets from internet to my IDS?