How to give clients IP Address, Gateways and DNS using OPNSense?

[Ciprian]

@Fabian, why a static LAN IP + reconfiguring the DHCP, since by default OPNsense would auto configure static LAN + DHCP on 192.168.1.0/24 that would not overlap 192.168.254.0 on the WAN?

I ask this only because he states (repeatedly) that's a novice in OPNsense/ networking, and leaving everything on default should do the trick perfectly for him, no fuss...

[Ciprian]

It has 4 ports LAN ports.

LAN1 -- LAN2 -- LAN3 --LAN/WAN

Where should I connect it? From modem to opnsense.

Theoretically, any of the 4, but I would go with LAN1, it will definitely work.

PS The last port is named LAN/WAN because your router is a mixed router, it can have WAN on a SIM (like it already does now) but also can be configured as a wired only GW, WAN being also a UTP cable, which case your last LAN port becomes the wired WAN port.

Still, try and see if you can configure your modem as a bridge. It would be perfect.
If not, at least in the modem configuration, try to DMZ OPNsense (192.168.254.110 - or whatever IP address will be in OPNsense for WAN)

[fabian]

@Fabian, why a static LAN IP + reconfiguring the DHCP, since by default OPNsense would auto configure static LAN + DHCP on 192.168.1.0/24 that would not overlap 192.168.254.0 on the WAN?

A lot of SOHO routers use this network and if you plan to do a Site to Site tunnel, it will not work because the network would be overlapping.
If no VPN is planned, this network should work without issues as well.

[Ciprian]

A lot of SOHO routers use this network and if you plan to do a Site to Site tunnel, it will not work because the network would be overlapping.
If no VPN is planned, this network should work without issues as well.

True!

I higly doubt that there will be any S2S VPN envolved... But if @agustinrojen foresee it, (s)he would act accordingly.

[GreG.P.]

LOL !

Why are you speaking about S2S vpn ?? seriously, I m agree with hutiucip to let the Maximum parameters by default for him because he doesn't have the basic network knowledge

Speaking and ask to perform advanced configure tasks to a user is the best way to lost customers/users

We should just help basic users and neophyte users about the solution witch are discuss around it.
Step by step

So next step is probably : How to replace our initial modem/router equipment by a single OPNsense utm
Enjoy it