RE: [Bridge] bridge MAC address

RE: [Bridge] bridge MAC address

[Levi Ariel-BAL023]

Stephen,

Thanks for your quick respond.

What do you mean by "later kernels"? I curently use kernel 2.4.20
Can I add a ioctl that enables modifying the bridge MAC address?

Thanks,
  Ariel


-----Original Message-----
From: Stephen Hemminger [mailto:shemminger@osdl.org] 
Sent: Thursday, March 02, 2006 10:31 PM
To: Levi Ariel-BAL023
Cc: bridge@lists.osdl.org
Subject: Re: [Bridge] bridge MAC address

On Thu, 2 Mar 2006 20:20:38 +0200
"Levi Ariel-BAL023" <ariel.levi@motorola.com> wrote:

> Hi,
> 
>  
> 
> I have notice that the bridge gets the "lowest" MAC address of its 
> interfaces.
> 
> Function: br_stp_recalculate_bridge_id()
> 
>  
> 
> Is there a meaning behind this or not?
> 
>  
> 
> Thanks,
> 
>  Ariel
> 

It's part of the Spanning Tree Protocol in the 802.1d standard.
In later kernels you can reset the address to be the same as any
of the interfaces being bridged.

Re: [Bridge] bridge MAC address

[Stephen Hemminger]

On Fri, 3 Mar 2006 10:03:04 +0200
"Levi Ariel-BAL023" <ariel.levi@motorola.com> wrote:

> 
> Stephen,
> 
> Thanks for your quick respond.
> 
> What do you mean by "later kernels"? I curently use kernel 2.4.20
> Can I add a ioctl that enables modifying the bridge MAC address?
> 
> Thanks,
>   Ariel
> 

I think I added it for 2.6.15

RE: [Bridge] bridge MAC address

[Levi Ariel-BAL023]

Stephen,
 Is there a patch I can add to 2.4.20 to have this functionality?
(Changing the bridge MAC address)?


-----Original Message-----
From: Stephen Hemminger [mailto:shemminger@osdl.org] 
Sent: Friday, March 03, 2006 5:38 PM
To: Levi Ariel-BAL023
Cc: bridge@lists.osdl.org
Subject: Re: [Bridge] bridge MAC address

On Fri, 3 Mar 2006 10:03:04 +0200
"Levi Ariel-BAL023" <ariel.levi@motorola.com> wrote:

> 
> Stephen,
> 
> Thanks for your quick respond.
> 
> What do you mean by "later kernels"? I curently use kernel 2.4.20
> Can I add a ioctl that enables modifying the bridge MAC address?
> 
> Thanks,
>   Ariel
> 

I think I added it for 2.6.15

Re: [Bridge] bridge MAC address

[Stephen Hemminger]

On Thu, 23 Mar 2006 15:28:50 +0200
"Levi Ariel-BAL023" <ariel.levi@motorola.com> wrote:

> Stephen,
>  Is there a patch I can add to 2.4.20 to have this functionality?
> (Changing the bridge MAC address)?
> 

No, at this point 2.4 is in maintenance mode only.

[Bridge] bridge MAC address

[Levi Ariel-BAL023]

[-- Attachment #1: Type: text/plain, Size: 214 bytes --]

Hi,

 

I have notice that the bridge gets the "lowest" MAC address of its
interfaces.

Function: br_stp_recalculate_bridge_id()

 

Is there a meaning behind this or not?

 

Thanks, 

 Ariel 


[-- Attachment #2: Type: text/html, Size: 2451 bytes --]

Re: [Bridge] bridge MAC address

[Stephen Hemminger]

On Thu, 2 Mar 2006 20:20:38 +0200
"Levi Ariel-BAL023" <ariel.levi@motorola.com> wrote:

> Hi,
> 
>  
> 
> I have notice that the bridge gets the "lowest" MAC address of its
> interfaces.
> 
> Function: br_stp_recalculate_bridge_id()
> 
>  
> 
> Is there a meaning behind this or not?
> 
>  
> 
> Thanks, 
> 
>  Ariel 
> 

It's part of the Spanning Tree Protocol in the 802.1d standard.
In later kernels you can reset the address to be the same as any
of the interfaces being bridged.

[Bridge] Bridge MAC address

[Nuutti Kotivuori]

Sorry, if this question has been answered before, but I could not find
out with a brief look.

How can I set the MAC address for a bridge? The MAC address given for
the bridge device seems to be the one it sends network packets with if
the bridge device has an IP address set. Apparently the bridge starts
with a zero MAC address and when the first interface is attached to
it, it takes its MAC address. When I try to set the MAC address, I
just get operation unsupported as a result.

I know I can probably cheat this by making a dummy interface, giving
it the MAC address I want and then attaching it to the bridge, but
this is but a crude workaround.

-- Naked

Re: [Bridge] Bridge MAC address

[Stephen Hemminger]

On Mon, 31 Jan 2005 12:29:09 +0200
Nuutti Kotivuori <naked@iki.fi> wrote:

> Sorry, if this question has been answered before, but I could not find
> out with a brief look.
> 
> How can I set the MAC address for a bridge? The MAC address given for
> the bridge device seems to be the one it sends network packets with if
> the bridge device has an IP address set. Apparently the bridge starts
> with a zero MAC address and when the first interface is attached to
> it, it takes its MAC address. When I try to set the MAC address, I
> just get operation unsupported as a result.
> 
> I know I can probably cheat this by making a dummy interface, giving
> it the MAC address I want and then attaching it to the bridge, but
> this is but a crude workaround.
> 
> -- Naked

The question is why do you need to set it at all? If this is some ISP
mac filtering issue, then set it on the first device before putting it into
the bridge.  I would be reluctant to change the bridge driver to accept
MAC address changes because of Spanning Tree and other standards related issues.

-- 
Stephen Hemminger	<shemminger@osdl.org>