if_bridge as if_vlan parent

[Tom Judge]

Josh Paetzel wrote:
> On Nov 21, 2009, at 11:39 AM, Tom Judge wrote:
> 
>> Hi,
>>
>> I was why I get the following error when trying to create a vlan on top of if_bridge:
>>
>> # ifconfig bridge0 create
>> # ifconfig vlan2 vlan 2 vlandev bridge0
>> ifconfig: SIOCSETVLAN: Protocol not supported
>>
>>
>> And if there was/is any reason for this to not be supported.
>>
>> Thanks
>>
> 
> 
> You can create a bridge from a pair of vlan devices....
> 
> # ifconfig vlan1 create
> # ifcconfig vlan2 create
> # ifconfig bridge0 create
> # ifconfig vlan1 vlan 1 vlandev em0
> # ifconfig vlan2 vlan 2 vlandev em0
> # ifconfig bridge0 addm vlan1 addm vlan2
> 
> Is that more in line with what you want to do?
> 
> I'm a little curious what problem set using a bridge as the parent of a vlan solves though.
> 
> 
You have the problem upside down.

I am trying to bridge 2 trunk ports on 2 separate switches with a 
FreeBSD box, and I would like to access a number of tagged vlans on the 
trunk with the FreeBSD box.

[sw1-1/g1]->[FBSD-em0]-[FBSD-bridge0]-[FBSD-em1]->[sw2-1/g1]
                          /       \
                 [FBSD-vlan2]    [FBSD-vlan200]

So:

ifconfig em0 up
ifconfig em1 up
ifconfig bridge0 create
ifconfig bridge0 addm em0 stp em0 addm em1 stp em1 up
ifconfig vlan2 create
ifconfig vlan2 10.0.0.1/24 vlan 2 vlandev bridge0
ifconfig vlan200 create
ifconfig vlan200 10.9.9.1/24 vlan 200 vlandev bridge0


This will fail when I try to attach the if_vlan's to the if_bridge.

Tom