Understanding OPNsense Gateways

[olluz]

Hi there,

can you please help me understand the OPNsense gateway handling ?

I have a fairly simple setup: WAN is attached to a VDSL modem using PPPoe and VLAN tagging (for the German Telekom)
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I then create another MODEM interface (just so I can access the modem's WebUi).
This will create another Gateway and set it to active (before creating the MODEM interface, WAN_PPPOE AND WAN_DHCP6 were active)
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Why does OPNsense create the interface in the first place and why is it active ?
When I try to disable the gateway this is the error that I am getting:
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Finally, when I try to delete the disabled Modem gateway, OPNsense will not delete it, but enable it and set it to active again !!!

What is the reasoning behind this behaviour ? Is this a bug ?

Thanks in advance!

[meyergru]

There are two variants of accessing an ONT or bridge modem on the WAN interface:

1. Assign the physical WAN interface and assign an IP range. This usually creates no gateway, unless you do it before you have set up a real WAN interface with PPPoE before. This variant works only, if your real WAN is on a VLAN and/or uses PPPoE.

2. Use a VIP on the physical WAN interface - this also works with a plain-vanilla DHCP setup on WAN. See: https://forum.opnsense.org/index.php?topic=36936.0

Maybe you should try deleting the MODEM interface, then the gateway and re-create the MODEM interface. It is not needed for your WAN connection, because you do not have to configure the parent interface for PPPoE or its underlying VLAN (unless you want to have modem access or you need to set hardware parameters).