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.