[VLAN] RE: My configuration in Bridge,802.1Q VLAN, and hotmail login, Thanks to all

[jzhang at cienettechnologies.com (kingz)]

Thanks to All!

I changed all two NICs on my Bridge box to Intel Pro/1000 MT card(with
Intel e1000 driver). I think they can handle larger frames with VLAN
tag. ( Thanks to Ben, Peter)

I also have one doubt: how to configure NICs and my bridge for larger
frames with VLAN tag?
I guess I need do so: (please correct me)
Bridge box: Redhat 9.0  Linux 2.4.28 kernel
1. Change NICs on bridge MTU to 1504 ( 0r other value)Is it necessary?
  ifconfig eth0(1) mtu 1504

2. Change bridge MTU to larger value? ( is it necessary?) 
I couldn't change the MTU of br0, I got the " SIOCSIFMTU: Invalid
argument" error. What's wrong with it?

Hemminger: For this patch in your reply, Do I need apply it to the
bridge code? As you know, the bridge code is built in the 2.4.28 kernel,
I also need apply this change to bridge code? And a stupid question:
where I apply it to? Which file?

Thanks!

Kingz







-----Original Message-----
From: Stephen Hemminger [mailto:shemminger@xxxxxxxx] 
Sent: 2004Äê12ÔÂ2ÈÕ 9:48
To: jzhang@xxxxxxxxxxxxxxxxxxxxxx
Cc: vlan@xxxxxxxxxxxx; ebtables-user@xxxxxxxxxxxxxxxxxxxxx;
bridge@xxxxxxxxxxxxxx; 'Derek Storvik'; greearb@xxxxxxxxxxxxxxx;
stuge-vlan@xxxxxxx; bdschuym@xxxxxxxxxx
Subject: Re: My configuration in Bridge,802.1Q VLAN, and hotmail login,
Thanks to all

On Thu, 2 Dec 2004 20:10:58 -0800
"kingz" <jzhang@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> Hi All,
> 
> For my issue, first thanks to ALL, I have some idea of it.
> Also Thank Peter for his kind remind, I would become one good guy in
> this list.
> 
> Most mentioned MTU, but how I assure that the problem is just MTU, how
I
> debug it?
> Here is my bridge configuration:
> Internet
>        |
>        |
>   Gateway
>        |
>        |   eth0
> Ethernet Bridge
>        |   eth1
>        |
>      H u b    ( one normal hub or switch , no VLAN settings)
>       |   \
>       |     \
>   D-Link  802.1Q VLAN Switches (their uplink port-port 1  connected to
> the upper hub are tagged, those ports connected with PCs are
untagged).
> 
> Bridge configuration:
> Linux 2.4.26 ( kernel built in bridge function)
> Eth0   RTL8139 driver
> Eth1   Intel e100 NIC with eepro100 driver
> 
> With VLAN tag, I met the hotmail login error, if without VLAN tag, all
> are OK!
> 
> Peter and Ben suggested me use intel NICs, I have one intel e100 NIC
and
> e1000 NIC, e1000 NIC is OK, but I cannt use the e100 card with the
e100
> driver( from both Linux 2.4.26 and Intel site e100-3.2.3), so I only
use
> eepro100 driver.
> How I can use the e100 with e100 driver? Can I use e100 and e1000
> together( use them as eth0,1)?
> Any one can help me?

There is some confusion about mtu and VLAN. Does mtu include VLAN tag or
not?
E100 allows the VLAN tag to be included (ie. actual_size >
nic->netdev->mtu
+ VLAN_ETH_HLEN)
but other drivers don't and the MTU reported to the bridge doesn't
include
the
VLAN tag. 

You could change:
	
int br_dev_queue_push_xmit(struct sk_buff *skb)
{
	if (skb->len > skb->dev->mtu) 
		kfree_skb(skb);
to:

int br_dev_queue_push_xmit(struct sk_buff *skb)
{
	if (skb->len > skb->dev->mtu + 4) 
		kfree_skb(skb);