[CentOS] bonding

Thu Apr 12 17:07:14 UTC 2007
Scott McClanahan <scott.mcclanahan at trnswrks.com>

On Thu, 2007-04-12 at 17:52 +0100, Richard Bellamy wrote:
> > I four nodes setup to do active-backup bonding and the drivers loaded
> > for the bonded network interfaces vary between tg3 and e100.  All
> > interfaces with the e100 driver loaded report errors much like what you
> > see here:
> >
> > bonding: bond0: link status definitely down for interface eth2,
> > disabling it
> > e100: eth2: e100_watchdog: link up, 100Mbps, full-duplex
> > bonding: bond0: link status definitely up for interface eth2.
> >
> > This happens all day on every node.  I have configured the bonding
> > module to do MII link monitoring at a frequency of 100 milliseconds and
> > it is using basic carrier link detection to test if the interface is
> > alive or not.  There was no custom building of any modules on these
> > nodes and the o/s is CentOS 4.3.
> >
> > Some more relevant information is below (this display is consistent
> > across all nodes):
> >
> > [smccl at tf35 ~]$uname -srvmpio
> > Linux 2.6.9-34.ELhugemem #1 SMP Wed Mar 8 00:47:12 CST 2006 i686 i686
> > i386 GNU/Linux
> >
> > [smccl at tf35 ~]$head -5 /etc/modprobe.conf
> > alias bond0 bonding
> > options bonding miimon=100 mode=1
> > alias eth0 tg3
> > alias eth1 tg3
> > alias eth2 e100
> >
> > [smccl at tf35 ~]$cat /proc/net/bonding/bond0
> > Ethernet Channel Bonding Driver: v2.6.1 (October 29, 2004)
> >
> > Bonding Mode: fault-tolerance (active-backup)
> > Primary Slave: None
> > Currently Active Slave: eth0
> > MII Status: up
> > MII Polling Interval (ms): 100
> > Up Delay (ms): 0
> > Down Delay (ms): 0
> >
> > Slave Interface: eth0
> > MII Status: up
> > Link Failure Count: 0
> > Permanent HW addr: 00:10:18:0c:86:a4
> >
> > Slave Interface: eth2
> > MII Status: up
> > Link Failure Count: 12
> > Permanent HW addr: 00:02:55:ac:a2:ea
> >
> > Any idea why these e100 links report failures so often?  They are
> > directly plugged into a Cisco Catalyst 4506.  Thanks.
> >
> > _______________________________________________
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> > CentOS at centos.org
> > http://lists.centos.org/mailman/listinfo/centos
> >
> 
> Hi
> 
> Maybe you could use use_carrier to check instead of miimon.
> 
> HTH
> 
> Richard
> 
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> 

I believe when you use miimon use_carrier defaults to 1 (more
modern/efficient carrier link detection).  Although it's not present in
the config, it is enabled.  I will test reverting to use_carrier 0
though to test and see if it more properly detects link status.