You can get by in either scenario if you utilize the native VLAN of 20 
for a default network when untagged packets are present.

I'm not sure if m0n0 supports any other native VLANs at this time

Neil A. Hillard wrote:
> Hi,
> 
> In message <45AD4219 dot 3020403 at boosten dot org>, Peter Boosten
> <peter at boosten dot org> writes
>> mtnbkr wrote:
>>> Peter Boosten wrote:
>>>> Hi all,
>>>>
>> [snip]
>>> First, you need to set the baystack port to "tagged trunk".
>>>
>>> Next, you need to create another VLAN and assign it to that port. Call
>>> the VLAN what you like, but this will be for the 192.168.13.0/24 network.
>>>
>>> I believe that here is where you went wrong:
>>> On the m0n0wall, in the Interfaces --> Assign page you need to configure
>>> your LAN interface to be the same VLAN that you just added to the
>>> baystack port for the 192.168.13.0/24 network.
>> Bill,
>>
>> Thanks for your answer.
>> So what you're basically saying is that one of the VLANs needs the same
>> IP address as the LAN interface?
>>
>>
>>> If your LAN interface is currently assigned to the hardware interface
>>> (sis0 on wrap - I do not know what m0n0 sees the ethernet ports as on a
>>> soekris) it will not work. The LAN interface needs to be on the correct
>>> VLAN.
>>>
>> This doesn't make sense: since it's a trunk, it'll be on several VLANs,
>> right?
> 
> I think the point is that you have to either use the physical device OR
> use VLANs, you can't use a combination, by setting an untagged VLAN on
> your switch.  Your LAN interface must be one of the VLAN devices.
> 
> I hope that's clearer!
> 
> HTH,
> 
> 
>                                 Neil.
>