I *WANT* NETDEV WATCHDOG to tell me eth2 is timing out, but it won't...
 

I'm working on a load balancer for outbound IP traffic across multiple DSL lines. When one of those lines fail the kernel has to detect this and stop using the line. I applied patches to the kernel to make this work. Can't tell you where I got them, the bloody forum won't let me :( but look at the loadbalancing section in the Advanced Routing HOWTO and you'll find them.

On my current test site I have the loadbalancer hooked up to the LAN via the Realtek card built into the motherboard (etth0). The DSL lines are on a Winbond NE2000 clone (eth1) and a 3Com card (eth2).
When I pull the cable out of eth1 the kernel detects this and a "NETDEV WATCHDOG: transmission timed out" message appears in the syslog, which is exactly what I want to happen.
However, when I pull the cable out of eth2 I don't get these messages, and the kernel keeps trying to send traffic over the disconnected eth2 interface.

So, how do I get the NETDEV WATCHDOG to bark?

TIA, Rogier

I have a stupid question. I looked at this advanced routing howto: http://tldp.org/HOWTO/Adv-Routing-HO...loadshare.html and I don't see any mention of kernel patching. Are you using an older or newer howto?

I haven't tried load balancing before, but I use the fair queueing system which is pretty much the same thing, just with one ethernet card. :)

Yeah, it was some other howto, but anyway the patches aren't important, it's just that the bloody kernel doesn't seem to notice me pulling the cable out of eth2.