em(4) on FreeBSD is sometimes annoying

Chris Rees utisoft at googlemail.com
Mon Aug 4 10:00:17 UTC 2008

Martin <nakal at web.de> wrote:

> On Sat, 02 Aug 2008 12:55:53 +0200
> Torfinn Ingolfsen <torfinn.ingolfsen at broadpark.no> wrote:
>> Just to be sure: also if the first command you try on the interface is
>> 'ifconfig up'?
> Hello Torfinn,
> good point, no. The problem appears when the first thing called on this
> interface is dhclient (caused by ifconfig_em0="DHCP"). I could also
> provoke this behavior after the interface was once up had an IP and was
> working (ping). All I need to do is to disconnect the NIC from the
> switch when I type "/etc/rc.d/netif restart".
> I have noticed further strange effects here. The behavior seems to
> be even more complex.
> After I typed "/etc/rc.d/netif restart", I waited until I get "giving
> up" message. Then I plugged the cable in. After about 30 seconds the
> link LED was on. I noticed that at this point I couldn't get an address
> using DHCP.
> So I disconnected physically the NIC (no cable) and link LED was
> still on! ifconfig showed me "state: active" with no cable plugged in.
> After further 30 seconds the LED went off.
> I attached the NIC again to the switch again and after 30 seconds
> again I got some other effect. The link LED went on (status: active)
> and the data LED was permanently blinking (about 2,5 times a second). I
> pulled the cable again and now the link LED is still on and the data
> LED still blinking (since about 10 minutes already).
> By the way...
> Now I'm typing this E-Mail without an ethernet cable plugged in and the
> link status LED is still on and the other data LED is blinking.
> --
> Martin
I may have misunderstood the purpose of this, but do you have the bpf
compiled into your kernel? If you're having DHCP troubles, this could
be a problem.


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