if_rl VLAN support in RELENG_4

[Dmitry Pryanishnikov]

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
rl(4), so I can rely on it. But it seems to be an overkill to upgrade an
average not-so-fast router to RELENG_6 just to be sure that rl(4) supports
1500-byte VLANs correctly, isn't it?


Sincerely, Dmitry
-- 
Atlantis ISP, System Administrator
e-mail:  dmitry at atlantis.dp.ua
nic-hdl: LYNX-RIPE