Detecting LINK_UP / LINK_DOWN events

[Nikos Vassiliadis]

On Tuesday 22 May 2007 12:19, Sastry Tumuluri wrote:
> > -----Original Message-----
> > From: Tom Judge [mailto:tom at tomjudge.com]
> > Sent: Tuesday, May 22, 2007 12:01 AM
> > To: Sastry Tumuluri
> > Cc: freebsd-net at freebsd.org
> > Subject: Re: Detecting LINK_UP / LINK_DOWN events
> >
> > Sastry Tumuluri wrote:
> > > Friends,
> > >
> > > I am trying to catch and do some extra processing on LINK_UP and
> > > LINK_DOWN events for my net interfaces (e.g., notify my
> >
> > admin, log the event, ...).
> >
> > > Tried this on both FreeBSD 6.1 and on FreeBSD 6.2.
> > >
> > > I tried using the devd.conf file with the following code (shows
> > > LINK_DOWN; wrote similar stuff for LINK_UP):
> > >
> > > notify 10 {
> > >    match   "type"    "LINK_DOWN";
> > >    action   "logger -s alert: Caught LINK_DOWN on dev: $device-name
> > > subsys:  $subsystem";
> > > };
> > >
> > > Didn't work. I tried the above with both strict match conditions
> > > (using vendor, device and class matches) as well as very
> >
> > general (like the above).
> >
> > > Didn't work.
> > > I ran killed devd and ran it in the foreground with "devd
> >
> > -dD". Then I
> >
> > > logged into a different pty and used
> > > ifconfig lnc0 down     #(lnc0 is my ethernet device).
> > > devd doesn't even seem to catch the event (no output at all
> >
> > - both on
> >
> > > screen and in syslog).
> > >
> > >
> > > On the other hand, "nomatch" and "attach" messages do seem to get
> > > through (I wrote similar stuff for nomatch & attach, and they are
> > > showing up at bootup and in syslog).
> > > What could I be doing wrong?
> >
> > Have you had a look at net/ifstated in ports?
> >
> > Tom
>
> Thanks, Tom! Though I had not heard of ifstated before this, it looks
> interesting. I've managed to quickly get the latest port and install it
> without any hassles - but am still a bit short on documentation - esp.,
> how the .conf file works, and how to make ifstated work for me. I
> haven't used carp so far; and am not sure whether I need to, if all I
> want is a simple "notification / logging". Any suggestions?
>
> On the other hand, I am still curious why devd didn't work in the first
> place. Is it a "futuristic" feature already advertised (in the devd.conf
> file, there are examples of LINK_UP/LINK_DOWN that make it look like it
> should work)? Or a case for better documentation?

Did you try pulling the plug?
LINK events refer to the change of link status, not
the "UP" status. That is the "status: active" line .

nik:0:~$ ifconfig fxp0
fxp0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=8<VLAN_MTU>
        inet 192.168.1.71 netmask 0xffffff00 broadcast 192.168.1.255
        ether 00:0c:f1:b9:38:50
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active

HTH, Nikos