Single NIC Setup

[Tesuci]

Hello everyone,

I am currently using a dual NIC Setup where the igc0 is used for the LAN Interface and igc1 is used for WAN. This was nice to get going and is the basic setup as far as I can tell.

However, since I moved and now only have to option to use a single ethernet cable between the OPNsense and the managed switch I will have to change to a single NIC setup.

Here is what I did and what problems I came across where I would need help.

I created 2 additional VLANs. One called LAN_VLAN with the ID 98 and one called WAN_VLAN with the ID 99. Both have the parent interface on igc0.

Now I assigned the 98 and activated it with static IP on 192.168.98.1 and also enabled the DHCP. (currently i'm using only IPv4 to reduce complexity).
Then I updated the switch to have port 1 with only VLAN99 untagged and port 2 with VLAN98 + 99 tagged. I then plugged the OPNsense to port 2 and the modem to port 1.

When I plugged in a laptop to the switch I recieved the desired IP Range.

Now the tricky part began. Getting the WAN configured.

I activated the WAN_VLAN with DHCP instead of static IP. There was no Gateway installed automatically so I copied the existing one and changed the interface. Then I disabled the old gateway to not have 2 upsteam gateways.

However I won't get a IP Adress from my provider. No reboot of the devices helped.
I don't know where I went wrong or what I need to make it happen.

Additional information: The modem is a Vodafone Station and the connection is made via cable internet.

I hope some of you can help. Thanks a lot!