Re: eth0 carrier wrongly seen on

[Sébastien Mazy <melyadon gmail com>]

On Fri, Jan 16, 2009 at 03:24:23PM -0500, Dan Williams wrote:
> Carrier detection is driven by netlink events, so the issue could be in
> a number of places.  To do top-level debugging, when you plug a cable in
> and unplug it again, does anything happen in the log?

Thanks for your really quick reply. Here are a few more tests.

Situation:
 - no cable connected
 - wlan0 configured by NM
 - static eth0 configured by NM

Action:
 - plug the cable in

/var/log/messages.log:

0000:00:19.0: eth0: Link is Up 100 Mbps Full Duplex, Flow Control: RX/TX
0000:00:19.0: eth0: 10/100 speed: disabling TSO
ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready

Action:
 - unplug the cable

/var/log/messages.log:

0000:00:19.0: eth0: Link is Down
NetworkManager: <info>  (eth0): carrier now OFF (device state 8)
NetworkManager: <info>  (eth0): device state change: 8 -> 2
NetworkManager: <info>  (eth0): deactivating device (reason: 40).
NetworkManager: <info>  Policy set 'Auto my_wifi_network' (wlan0) as default for routing and DNS.

Action:
 - plug the cable in

/var/log/messages.log:

0000:00:19.0: eth0: Link is Up 100 Mbps Full Duplex, Flow Control: RX/TX
0000:00:19.0: eth0: 10/100 speed: disabling TSO
NetworkManager: <info>  (eth0): carrier now ON (device state 2)
NetworkManager: <info>  (eth0): device state change: 2 -> 3
NetworkManager: <info>  Activation (eth0) starting connection 'home static'
NetworkManager: <info>  (eth0): device state change: 3 -> 4
NetworkManager: <info>  Activation (eth0) Stage 1 of 5 (Device Prepare) scheduled...
NetworkManager: <info>  Activation (eth0) Stage 1 of 5 (Device Prepare) started...
NetworkManager: <info>  Activation (eth0) Stage 2 of 5 (Device Configure) scheduled...
NetworkManager: <info>  Activation (eth0) Stage 1 of 5 (Device Prepare) complete.
NetworkManager: <info>  Activation (eth0) Stage 2 of 5 (Device Configure) starting...
NetworkManager: <info>  (eth0): device state change: 4 -> 5
NetworkManager: <info>  Activation (eth0) Stage 2 of 5 (Device Configure) successful.
NetworkManager: <info>  Activation (eth0) Stage 3 of 5 (IP Configure Start) scheduled.
NetworkManager: <info>  Activation (eth0) Stage 2 of 5 (Device Configure) complete.
NetworkManager: <info>  Activation (eth0) Stage 3 of 5 (IP Configure Start) started...
NetworkManager: <info>  (eth0): device state change: 5 -> 7
NetworkManager: <info>  Activation (eth0) Stage 4 of 5 (IP Configure Get) scheduled...
NetworkManager: <info>  Activation (eth0) Stage 3 of 5 (IP Configure Start) complete.
NetworkManager: <info>  Activation (eth0) Stage 4 of 5 (IP Configure Get) started...
NetworkManager: <info>  Activation (eth0) Stage 5 of 5 (IP Configure Commit) scheduled...
NetworkManager: <info>  Activation (eth0) Stage 4 of 5 (IP Configure Get) complete.
NetworkManager: <info>  Activation (eth0) Stage 5 of 5 (IP Configure Commit) started...
NetworkManager: <info>  Policy set 'Auto my_wifi_network' (wlan0) as default for routing and DNS.
NetworkManager: <info>  (eth0): device state change: 7 -> 8
NetworkManager: <info>  Policy set 'home static' (eth0) as default for routing and DNS.
NetworkManager: <info>  Activation (eth0) successful, device activated.
NetworkManager: <info>  Activation (eth0) Stage 5 of 5 (IP Configure Commit) complete.

> Failing that,
> we'll need to make a netlink carrier test tool to show what's happening
> on netlink and see if the kernel/driver is lying to us or not delivering
> events.

Another detail: the problem only occurs on the first start of NM. If I
stop it and start it again, I'm connected through wlan0 and NM
acknowledges there is no cable plugged.

With these elements, it seems unlikely that the problem is related to
NM. I'm interested in monitoring netlink messages though. Are there some
tools to do so?


(I'm sorry Dan I hadn't noticed that this ML didn't set the Reply-To,
and so you may receive this mail twice)


Cheers,

-- 
Sébastien Mazy