[CentOS] CentOS 5.7 Ethernet bonding - order of enslavement matters?

Wed Oct 19 08:21:02 UTC 2011
whitivery <co55-sy1t at dea.spamcon.org>

Emmanuel Noobadmin <centos.admin at gmail.com>
wrote:

>On 10/13/11, whitivery <co55-sy1t at dea.spamcon.org> wrote:
>>>Eth0 is the onboard device, using an updated VIA Velocity driver
>>>(velocityget 1.42 instead of default via-velocity):
>>>
>>>05:00.0 Ethernet controller: VIA Technologies, Inc. VT6120/VT6121/VT6122
>>>Gigabit Ethernet Adapter (rev 82)
>>>
>>>Eth1 is a Linksys (Cisco) USB300M USB-Ethernet dongle, using asix
>>>driver:
>
>Have you tried adding another Ethernet adapter? This is because I was
>reading the bonding doc and towards the end there was this part
>
>>As discussed in the options section, above, some drivers do
>>not support the netif_carrier_on/_off link state tracking system.
>>With use_carrier enabled, bonding will always see these links as up,
>>regardless of their actual state.
>
>So it might a driver issue, i.e. the VIA driver is not reporting the
>link down correctly.

Thank you for the reply, but I don't think that this is the issue.
Otherwise bonding failover wouldn't work at all.  When enslaved in order
eth1 eth0, bonding and link detection work properly - with eth0 set as
primary, I pull the eth0 cable, it switches to eth1; plug eth0 back in, it
switches back to it; pull the eth1 cable, it knows there's no fallback.
So the link detection seems fine.