Trouble configuring network bridge

[Raging_Flames]

I'm trying to configure a network bridge on my new router and am having trouble. My computer has an onboard 1g nic attached to the motherboard and I added an intel x520 and x540 to the computer. Right now, one of the ports on the x540 is my lan port, but I'd like to connect all 4 ports to be lan, and make it so that computers plugged into any of those 4 ports can talk to each other. I've set up a test bridge for just the x540, but when I try to assign it to lan, opnsense complains that my lan port is in use. But I can't unassigned my lan port because I'm using that to talk to opnsense... I'm not really sure how to proceed. I've been following this guide:
https://docs.opnsense.org/manual/how-tos/lan_bridge.html
And it seems to mostly line up with what I see, but it looks like some screenshots/wording is out of date. If anyone has done this before and understands what I need to do I would appreciate any guidance.

[Monviech (Cedrik)]

It seems you have a lot of interfaces, so just assign one with a different IP address (e.g. 192.168.34.1/24) and connect your PC to that.

That way you have an inband management interface.

[Raging_Flames]

Yeah, I know I have more than usual, this solution was just cheaper (And I was hoping easier) than getting highspeed network switches. I think I tried what you suggested, I say I think because I may have messed up a step.

One of the things that is really stumping me is under interfaces/assignments all the guides make it seem as though you can set the lan port or change the assignment for an interface, but that doesn't seem to be the case. The identifier can not be changed on my screen, and is tied to an interface that can also not be changed. The only thing I can change is the device attached to that interface/identifier. You can kind of see this in my pictures.

I took the second port on the x540, assigned it an ip, then went and added the all the other ports to the bridge. When I got to the assignments page, I tried to assign the bridge to the lan identifier but still no luck.

[Monviech (Cedrik)]

Im not sure why you configured the bridge on WAN and LAN, dont you only want to simulate a switch?

For that you dont need a transparent filtering bridge.

Just put a few ports into a bridge, assign it, and use it. You dont have to assign it to LAN. LAN and WAN arent special identifiers. Each interface will get an optX name (so your bridge can become opt1 for example) and you can configure the network you want to use on it.

LAN interface can be deleted it doesnt matter in the setup since its not special. Just make sure you keep the additional management interface so you dont lock yourself out.

Though switches arent expensive, there are 8 port netgear switches for 50-60€/$.

[EricPerl]

Given the cards he added, the OP is likely to want multi-gig switching.
I'm not sure I'd want to do that in software...
Multi-gig hardware switches tend to be more expensive than €60.

@OP:
If you're connected to OPN via a port that you ultimately want to be part of the bridge, you can't include that port in the bridge from the get-go. You create the bridge with the other port(s), reassign the parent interface to the bridge, then reconnect the managing PC to one of the ports of the bridge (see note in step 3).
Then you go back in, and update the bridge to include the original port.

This said, given your setup, I also encourage you to use the onboard interface as a management interface, in case your bridge misbehaves. If you don't have a physical gigabit switch, you'll need to plug a PC directly (with a compatible IP).
Scratch that. The onboard is likely used for WAN, although the assignments don't show that. WAN -> em0?

[Monviech (Cedrik)]

Good catch totally missed its 10G cards.

[Raging_Flames]

That's entirely my bad with the bridge screenshot. I did try to assign the bridge to the lan interface and get the same error as shown in the new screenshot. I must have missclicked or something in the first picture, that's entirely my bad.

I am very sorry if I'm misunderstanding what either of you are saying, I'm kind of new to this and am trying to break in with this setup in my new apartment. I'll try to address all your questions and comments.

I've assigned an IP to the second port just like I showed in the picture from my second post. I've also tried to just assign ix0 to the lan, and then place ix0 in a bridge with the other ports, neither really did what I thought it would do. Similarly, putting ix0-ix3 in a bridge and assigning that to lan doesn't work with the error attached in the new picture.

Yes, I am looking to have multigig networking, I was not aware that that could cause problems for me. If I had to guess it'll probably be because of a cpu bottle neck due to no hardware acceleration? I think for now I'm willing to bite that bullet until I can actually afford a multi gig switch, I'm just trying to increase the lan connection speed between my desktop computer and the server I'm running proxmox on.

The onboard interface is assigned to wan, I've double checked and that is connected to the box from my isp.

I do really appreciate you two sticking with me this long, if you know what I'm doing wrong please share it with me so I can hopefully figure this out.

[EricPerl]

So you start from:
WAN -> em0
LAN -> ix0 (static IP + DHCP)
The mgmt PC is connected to ix0.

You add the bridge and include the OPT for ix1-3 (step 2)
You re-assign LAN to the bridge (step 3)
As soon as you do this, you lose connectivity to OPN. You need to plug the mgmt PC into ix1 or greater, wait some

When you get back in, ix0 is now unassigned. Assign it (step 4) and add it to the bridge (step 5).

Where do you get stuck?

If you can't get back in after step 3 (and some patience), you'll need to re-assign LAN to ix0 from the console...

[Raging_Flames]

I finally got a chance to try the steps you outlined when my roommate was out. I'm not sure what I was doing wrong, but your steps helped me out and I eventually got it. I know at one point I got on the computer directly and reloaded all the services, and it seemed to all come together after that. I did a speed test and I'm really pleased with the results! I was able to easily get 10gb/s with only about a core and a half of my cpu which is perfect. Thank you so much for all your help everyone.