[Bridge] Monitor the status of two ethernet interface

[Jie Chen]

Thank you, Stephen.


I'm reading the codes. The software uses ioctl a lot. I'm new to ioctl, is 
it an interface between register values of the ethernet card and user 
application?


We use ioctl to add a bridge, add an interface to the bridge, which ioctl 
file do we use for that? I greped the whole file system of my linux box, I 
found some ioctl files, but when I try to match the cases (The second 
parameter such as SIOCSIFBR, SIOCBRADDBR) it handles, it seems none of those 
files match our cases.


Another question I had is about my understanding on ioctl. Since I think 
ioctl is just to set physical register values of ethernet cards, once it's 
set, all the functions should be automatic, when packets come, the bridge 
automatically routes, is Kernel involved in those functions?


About STP, seems like everything is set by a function br_set, and eventually 
by ioctl. Is there any daemon to maintain STP?


Thanks again for your valuable time.
Jie

>From: Stephen Hemminger <shemminger at osdl.org>
>To: "Jie Chen" <cj70286 at hotmail.com>
>CC: bridge at lists.osdl.org
>Subject: Re: [Bridge] Monitor the status of two ethernet interface
>Date: Wed, 20 Dec 2006 14:32:09 -0800
>
>On Wed, 20 Dec 2006 21:26:18 +0000
>"Jie Chen" <cj70286 at hotmail.com> wrote:
>
> > Hi everybody,
> >
> > Just have myself added into the maillist. I have a few linux boxes with
> > Kernel 2.6.9. Each box has 2 ethernet interfaces, one 3COM, one Intel. I
> > connected one with Power Line Modem, and one with Wifi Modem. They form 
>a
> > nice network with bridge. I have a few questions here.
> >
> > Suppose I have two path from box A to box D, which path will packets go
> > through? If I want to monitor the condition (throughput) of each 
>interface,
> > and pick the better one, how do I do it? If I want to use both 
>interfaces to
> > transfer data, how do I do it?
>
>With STP it will choose the "least cost" which is determined by the port
>cost variable. In 2.6, it automatically sets the cost based on link speed. 
>but
>then you can change it later with brctl
>
> >
> > Thanks in advance for your answers,
> > cj
> >
> > _________________________________________________________________
> > Type your favorite song.  Get a customized station.  Try MSN Radio 
>powered
> > by Pandora. http://radio.msn.com/?icid=T002MSN03A07001
> >

_________________________________________________________________
Get FREE Web site and company branded e-mail from Microsoft Office Live 
http://clk.atdmt.com/MRT/go/mcrssaub0050001411mrt/direct/01/