[CentOS] How to make a network interface come up automatically on link up?

Tue Mar 26 01:34:02 UTC 2013
Earl Ramirez <earlaramirez at gmail.com>

On Mon, 2013-03-25 at 18:09 -0600, Joakim Ziegler wrote:
> On 24/03/13 4:01, Nux! wrote:
> > On 24.03.2013 02:27, Joakim Ziegler wrote:
> >> I have a recently installed Mellanox VPI interface in my server. This
> >> is
> >> an InfiniBand interface, which, through the use of adapters, can also
> >> do
> >> 10GbE over fiber. I have one of the adapter's two ports configured for
> >> 10GbE in this way, with a point to point link to a Mac workstation
> >> with
> >> a Myricom 10GbE card.
> 
> >> I've configured this interface on the Linux box (eth2) using
> >> /etc/sysconfig/network-scripts/ifcfg-eth2 , setting its IP address,
> >> MTU,
> >> subnet, etc.
> 
> > Try adding HOTPLUG=yes in the cfg file.
> 
> Neither HOTPLUG=yes or MANAGED=no seems to make this interface come back
> up when the cable is unplugged and then plugged, unfortunately. For
> instance, before unplugging anything, ifconfig says:
> 
> eth2      Link encap:Ethernet  HWaddr 00:02:C9:29:64:8F
>              inet addr:10.10.0.1  Bcast:10.10.255.255  Mask:255.255.0.0
>              inet6 addr: fe80::2:c900:129:648f/64 Scope:Link
>              UP BROADCAST RUNNING MULTICAST  MTU:9000  Metric:1
>              RX packets:47 errors:0 dropped:0 overruns:0 frame:0
>              TX packets:26 errors:0 dropped:0 overruns:0 carrier:0
>              collisions:0 txqueuelen:1000
>              RX bytes:14924 (14.5 KiB)  TX bytes:3940 (3.8 KiB)
> 
> Then I unplug the cable, which, in dmesg, gives me:
> 
> mlx4_en: eth2: Link Down
> 
> And in /var/log/messages:
> 
> Mar 25 11:36:24 resolve02 ntpd[4819]: Deleting interface #14 eth2,
> 10.10.0.1#123, interface stats: received=0, sent=0, dropped=0,
> active_time=163 secs
> 
> (Which I guess is just ntpd reacting)
> 
> And then I plug the cable back in, and in dmesg, I have:
> 
> mlx4_en: eth2: Link Up
> 
> Mar 25 11:38:09 resolve02 kernel: mlx4_en: eth2: Link Up
> Mar 25 11:38:09 resolve02 NetworkManager[4429]: <info> (eth2): carrier
> now ON (device state 2)
> Mar 25 11:38:09 resolve02 NetworkManager[4429]: <info> (eth2): device
> state change: 2 -> 3 (reason 40)
> 
> But ifconfig gives me:
> 
> eth2      Link encap:Ethernet  HWaddr 00:02:C9:29:64:8F
>              inet6 addr: fe80::2:c900:129:648f/64 Scope:Link
>              UP BROADCAST RUNNING MULTICAST  MTU:9000  Metric:1
>              RX packets:104 errors:0 dropped:0 overruns:0 frame:0
>              TX packets:26 errors:0 dropped:0 overruns:0 carrier:0
>              collisions:0 txqueuelen:1000
>              RX bytes:25567 (24.9 KiB)  TX bytes:3940 (3.8 KiB)
> 
> So no IP address, and no joy. ifup eth2 brings me back to:
> 
> eth2      Link encap:Ethernet  HWaddr 00:02:C9:29:64:8F
>              inet addr:10.10.0.1  Bcast:10.10.255.255  Mask:255.255.0.0
>              inet6 addr: fe80::2:c900:129:648f/64 Scope:Link
>              UP BROADCAST RUNNING MULTICAST  MTU:9000  Metric:1
>              RX packets:104 errors:0 dropped:0 overruns:0 frame:0
>              TX packets:41 errors:0 dropped:0 overruns:0 carrier:0
>              collisions:0 txqueuelen:1000
>              RX bytes:25567 (24.9 KiB)  TX bytes:6493 (6.3 KiB)
> 
> Ideas?
> 

I am just shooting in the dark what happen if you have NM_CONTROLLED=yes
in the eth2 network script?
-- 


Kind Regards
Earl Ramirez
GPG Key: http://trinipino.com/PublicKey.asc
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