LAN Interface with it's own external gateway

[skb1]

Hi all,
I'm running a pilot OPNsense deployment on bare metal and encountered a problem related to LAN access.
Setup:

- LAN interface with a static IP and an upstream gateway (external router)
- WAN1 and WAN2 in different VLANs with static public IPs and gateways
- Web UI is accessed via the LAN interface
- LAN needs to route traffic through its own upstream router, not through WAN

Issue:
As soon as I assign a default gateway (e.g., WAN1) under System → Routing → Gateways, access to the Web UI over LAN breaks.

Even with a firewall rule like:
    Source: LAN net
    Destination: This firewall
    Gateway: default or specific
    Advanced: Disable reply-to → enabled

...the connection is lost.

Tried:
    Removing all default gateways — Web UI becomes reachable again
    Adding a static route for the LAN subnet via the upstream LAN gateway
    Testing different firewall rule orders and combinations
    pfctl -d does not restore access

Goal:
I want to maintain stable access to the Web UI via LAN (which routes through its own upstream router) while still having a default gateway active on WAN for general internet access.

Is there a correct or recommended way to achieve this in OPNsense?

Thanks in advance!

[viragomann]

As soon as I assign a default gateway (e.g., WAN1) under System → Routing → Gateways, access to the Web UI over LAN breaks.

You access the Web UI from a LAN device or from outside?

Access from the LAN subnet should be possible at all. If that's not working check the network settings on the involved devices.