if_vlan subinterfaces at boot

[Steve Bertrand]

Brooks Davis wrote:
> On Mon, Jun 16, 2008 at 09:22:32PM -0400, Steve Bertrand wrote:
>> Steve Bertrand wrote:
>>> Brooks Davis wrote:
>>>> On Mon, Jun 16, 2008 at 08:27:47PM -0400, Steve Bertrand wrote:
>>>>>> Is there any way to create, and assign addresses to a if_vlan 
>>>>>> sub-interface (eg: em6.3) via rc.conf at boot?

>> Now, my next question is, can I have interface em6.7 operate on multiple 
>> vlans? ie, change the default behavior of the if_vlan interface's implicit 
>> designation to only vlan 7?
>>
>> I want to have multiple prefixes (ie: subnets) within a single broadcast 
>> domain, but each prefix on its own sub-interface on the FreeBSD box, 
>> without designating a VLAN for each. (Please forgive the IPv6 test above, 
>> as it probably misguides my efforts... my tests at this point are purely to 
>> *hopefully* meet an IPv4 conceptual design goal).
>>
>> Is this possible?
> 
> Currently there's no easy way to assign multiple interfaces for the same
> broadcast domain.  In theory, if you could create some sort of virtual
> ethernet device you could bridge one to the real interface for each
> subnet.  I don't think we have such a device in the tree at the moment,
> but I don't think they are very hard to create in principle.

Brooks, et-al,

I am attempting to simulate (at this point) relatively basic Cisco 
router capabilities with the complete understanding that FreeBSD is an 
OS and can NOT be used as-is for Cisco emulation.

My conceptual tests are in conjunction with the functionalities of 
Quagga routing suite. (Which, according to personal experience with it's 
implementation and this thread:

http://forums.whirlpool.net.au/forum-replies-archive.cfm/335988.html

...is not/can not be taken as a Cisco simulator/emulator in any form). 
Quagga does (IMHO) a relatively decent job of making it easy to 
transition from production Cisco gear to USB thumbdrive bootable lab 
gear very quickly, running on commodity hardware.

In theory (I am no where near an expert with FBSD network 
implementation), would it be possible to use the likes of if_bridge to 
undermine if_vlan interfaces?

More importantly, has my request made any sense, and if so, does anyone 
else have interest in a specification for it? If so, how would one go 
about requesting such a specification/implementation?

Does anyone else use this sort of setup, how do you do it currently?

High level overview:

- numerous physical interfaces
- several logical (ie: subnets) per interface
   - each 'subnet' on each interface connected via sub-int (no vlan tags)
   - no implicit vlan designation, or;
   - the ability to create manual 'broadcast domain' subints
   - ability for an equivalent 'sw-acc vlan xx' on a sub-int directly 
to 	    take it *out* of a default implied vlan (I haven't tested this)

...I know with the former I'm pretty well pushing the boundaries of what 
FreeBSD has ever been designed for, but I've known it to be robust in 
everything that it does, particularly to it's network stack.

Anything I can and have thought about would depend on the implementation 
of the routing 'suite', and not FreeBSD in itself. Perhaps most of what 
I've asked about is out of scope, but I need to ask.

If anyone can provide me with information on specific working groups or 
locations that I can directly obtain information for certain areas 
without disturbing the list, I would be appreciative.

Currently, I am deeply focused on the above, and:

- 7.0 and IPv6 jails
- work/compliance within the scope of RFC 4861 & 4862
- implementation regarding RFC 3484
- how a user (granted, 'user' in this case fully understands that most 
all hands on deck are not paid for their 'job') can find out when/if 
drafts are being considered:

http://www.ietf.org/internet-drafts/draft-ietf-v6ops-addr-select-ps-08.txt

...as one example.

Steve