freebsd stable - Aug 2008 - should looking at an interface with 'ifconfig' trigger a change ?

I have a very odd problem here - two interfaces bundled using lagg
in 'failover' mode, so one interface is active and the other not being
used. if the carrier drops on the active one I expect it to
failover, but it doesnt.

...until I type 'ifconfig bce0' to look at the status of the interface
which has gone down. At which point it fails over properly!

This is most odd - how can simply looking at the config of an
interface trigger the failover ? It wont fail over otherwise either - you
can leave it as long as you like and lagg wont realise that the active
has gone down.

The interfaces here are 'bce' by the way, if that make a difference....

-pete.

> The bce driver is not properly generating link state events.
OK, that explains why it doesnt failover - but why does looking at it
with ifconfig make a difference ? surely that should be 'read only ?

-pete.

On Thu, Aug 07, 2008 at 05:27:53PM +0100, Pete French
wrote:
> I have a very odd problem here - two interfaces bundled using lagg
> in 'failover' mode, so one interface is active and the other not
being
> used. if the carrier drops on the active one I expect it to
> failover, but it doesnt.
> 
> ...until I type 'ifconfig bce0' to look at the status of the
interface
> which has gone down. At which point it fails over properly!
> 
> This is most odd - how can simply looking at the config of an
> interface trigger the failover ? It wont fail over otherwise either - you
> can leave it as long as you like and lagg wont realise that the active
> has gone down.
> 
> The interfaces here are 'bce' by the way, if that make a
difference....
The bce driver is not properly generating link state events.


Andrew

On Thu, Aug 07, 2008 at 05:27:53PM +0100, Pete French wrote:
 > I have a very odd problem here - two interfaces bundled using lagg
 > in 'failover' mode, so one interface is active and the other not
being
 > used. if the carrier drops on the active one I expect it to
 > failover, but it doesnt.
 > 
 > ...until I type 'ifconfig bce0' to look at the status of the
interface
 > which has gone down. At which point it fails over properly!
 > 
 > This is most odd - how can simply looking at the config of an
 > interface trigger the failover ? It wont fail over otherwise either - you
 > can leave it as long as you like and lagg wont realise that the active
 > has gone down.
 > 
 > The interfaces here are 'bce' by the way, if that make a
difference....
 > 

Try attached patch and check whether bce(4) correctly reports link
state changes.

After seeing 'link state changed to UP' message, unplug the cable
and see whether it reports link DOWN. The message should be printed
in a second. Also try replugging cable and you should see link UP
message within several seconds. Since auto-negotation takes more
time you may have to wait for a while.

-- 
Regards,
Pyun YongHyeon
-------------- next part --------------
--- sys/dev/mii/brgphy.c.orig	2008-01-22 10:23:10.000000000 +0900
+++ sys/dev/mii/brgphy.c	2008-01-22 12:32:41.000000000 +0900
@@ -364,16 +364,13 @@
 			break;
 		}
 
-#if 0
-		/* Todo: Is this correct? */
 		/* Announce link loss right after it happens. */
 		if (sc->mii_ticks++ == 0)
 			break;
-#endif
 
 		/* Only retry autonegotiation every mii_anegticks seconds. */
 		if (sc->mii_ticks <= sc->mii_anegticks)
-			goto brgphy_service_exit;
+			break;
 
 
 		/* Retry autonegotiation */