They do, is the xl* driver.
After wrestling with this problem for months I have switched to pfsense.
Communication between vlans works now.
> On Wed, May 7, 2008 at 8:31 PM, <eric dot lopez at ues dot edu dot sv> wrote:
>> We have monowall installed with four interfaces one of them is the WAN interface
>> the other three manage 14 different tagged vlans. Users (about 300) browse the
>> web without a problem. connectivity between vlans works at a basic level
>> meaning that pinging any host works well but moving files between vlans is
>> impossible. I have tested in many different ways, and proved that moving an 8
>> bytes empty text file works flawlessly but anything bigger gets the network
>> hang. However I can move the same big file outside monowall into another public
>> IP without a problem.
>> This is not a rules problem, the logs do not show anything being blocked.
> What kind of NIC's are you using/do they support VLAN tagging on m0n0wall?