if_rl VLAN support in RELENG_4

[Sten Daniel Sørsdal]

Dmitry Pryanishnikov wrote:
> 
> Hello!
> 
> On Wed, 12 Jul 2006, Sten Daniel S?rsdal wrote:
>>>   In RELENG_4, RealTek 8129/8139 driver rl(4) doesn't claim VLAN support
>>> (when I assign vlandev rl0, my vlan device initially gets mtu 1496). In
>>> modern (e.g. RELENG_6) systems if_rl claims native VLAN support. I've
>>> tried setting 'ifconfig vlan0 mtu 1500' for rl-based vlan device, and
>>> resulting interface Just Works (TM) (1500-byte packets trasmit and
>>> receive
>>> correctly via such a vlan). So is it safe to use vlan with 'vlandev rl0'
>>> and 'mtu 1500' in RELENG_4? Has anyone observed any ill-effects in such
>>> a configuration? Would it be simple enough for if_rl in RELENG_4 to
>>> just announce native VLAN support to the system?
>>>
>>> Sincerely, Dmitry
>>
>> Not necessarily. I would assume, without looking, that you would also
>> need to enable oversized frame support.
> 
>  I'm curious whether you've missed the following:
> 
>>> I've
>>> tried setting 'ifconfig vlan0 mtu 1500' for rl-based vlan device, and
>>> resulting interface Just Works (TM).
> 
> So the required support seems to be already enabled (at least for my
> particular NIC). It isn't question for me whether _my_ NIC works in this
> mode - it definitely does. My question is whether _any_ rl(4)-supported
> card will behave in the same way ( = can I _rely_ on rl(4) in RELENG_4
> being able to do 1500-byte VLANs). In RELENG_6, e.g., this capability is
> announced by the

Aha. I'm not sure i can answer that. I was under the impression that not
all realtek cards supported oversized frames (notably 8129 with an
external phy) and that 8139 A and B series were a little shakey but C is
definitly fine. 8139 had internal PHY so i guess they (a/b/c) are pretty
similar.

I can however not really give you the answer you are looking for, sorry.

-- 
Sten Daniel Sørsdal