Only one physical LAN port works at any given moment

[New_User]

Hello all,

I'm a new OPNsense user, so apologizes for the noobish questions :)

I installed OPNsense on a 4-port Topton mini pc I purchased from Aliexpress.

Save for the fact that it gets VERY hot under normal load, I'm quite happy with it.

However, recently I decided to connect my laptop directly to the Topton mini pc, and it turned out, that at any given moment only one LAN port works (ETH1 or ETH2). I need to disconnect one of them from the OPNsesne machine (Topton) so the second one will have internet access (or even access to OPNsense itself).

ETH0 is the WAN port.
ETH1 goes to the AP.
ETH2 goes to my laptop (this is the new interface I configured recently).

It seems that both of the interfaces (ETH1 and ETH2) provide a valid IP address in the configured range, but until I disconnect one of them, there is no internet access on both of them (and while both of them are connected I can not access OPNsense interface).

* I did change many settings on ETH1 interface (to work with VLAN's, VPN etc), but I'm not sure why should it have any effect on a separate interface (ETH2).

** I understand that there is no bridge by default between the interfaces, but this is not what I'm trying to achieve.

What can be the issue? Where should I start looking for a solution?

Any help would be highly appreciated!

Thank you.

[requird]

I'm using one of those machines. I like it.

I don't know what the problem is, but I just want to make sure you did some things first.

I have LAN1, LAN2, LAN3, and WAN assigned in the interfaces.
Each LAN has a different network range. For example:
LAN1 192.168.1.0/24
LAN2 192.168.2.0/24
LAN3 192.168.3.0/24

Then, DHCP each LAN.

Is this similar to your setup?

[requird]

Sorry, I should be more clear.

LAN1 will be assigned the IP address 192.168.1.1.
LAN2 will be 192.168.2.1
LAN3 will be 192.168.3.1

Under Services -> DHCPv4
Set the subnet and mask to 192.168.1.0 and 255.255.255.0

Then configure the DHCP range.

This is like a basic configuration. Is this something like how yours is setup?

[New_User]

Hi and thanks for your reply!

Yep. I set different IP ranges, but the idea is the same.

It is worth mentioning, that sometimes, for an unexplained reason, it just works (without disconnecting the other LAN connection).  At this specific moment, it works, but yesterday it did not work.  :-\

Thank you.

[requird]

Maybe a hardware issue?

Do you have any switches in your network? Is there a possibility of a loop?