Re: [gentoo-user] Strange network behaviour: NIC goes down, DHCP lease renewal fails

[Marc Joliet <marcec@gmx.de>]

[-- Attachment #1: Type: text/plain, Size: 2306 bytes --]

Am Thu, 5 Mar 2015 21:19:46 +0000
schrieb Mick <michaelkintzios@gmail.com>:

> On Thursday 05 Mar 2015 18:33:23 Todd Goodman wrote:
> > * Marc Joliet <marcec@gmx.de> [150305 04:47]:
> > [..SNIP..]
> > 
> > > 1.) The NIC is brought up (some built-in Intel model).
> > > 
> > > 2.) A DHCP client configures it.
> > > 
> > > 3.) The network connection is lost at some point (the amount of time this
> > > takes
> > > 
> > >     varies, but it can be as little as 20 minutes).
> > > 
> > > 4.) Eventually the lease runs out and the DHCP client tries to renew it,
> > > but
> > > 
> > >     gets no response.  Sometimes, after many hours (at least 6), it will
> > >     get a DHCPACK, but that's it.  One of our sysadmins says that not
> > >     only does the DHCP server never see the packets, but the managed
> > >     switch that the PC is directly attached to *also* never does (again,
> > >     except for when the occasional DHCPACK comes).
> > > 
> > > 4.) Restart the network device.  A reboot is not required, but it is
> > > necessary
> > > 
> > >     to terminate the DHCP client.  After that everything works again.
> > > 
> > > 5.) GOTO 3.
> > 
> > [..SNIP..]
> > 
> > Is this a WiFi NIC?
> > 
> > Is it possible the device is powering down?
> > 
> > I've had lots of problems with WiFi devices powering down (both driver
> > issues as well as just trying to disable the default setting of powering
> > down.)
> > 
> > Todd
> 
> If not a WiFi, have you also tried to mirror a port at the router where the 
> DHCP server is running and sniff packets there?  Does the router see the 
> DHCPREQ coming through from the client PCs?

They apparently don't even reach the managed switch, which is what the PC is
directly connected to (but again: the third affected PC is on a different
switch).  I find this very confusing :-/ (and so does our local sysadmin, or
so I'm told).

(I have to mention that the best I can do is relay ideas here to my boss and the
aforementioned sysadmin, as I don't have access to any of the network
hardware and software, save for the affected PCs.  I am mostly trying to
collect ideas.)

-- 
Marc Joliet
--
"People who think they know everything really annoy those of us who know we
don't" - Bjarne Stroustrup

[-- Attachment #2: Digitale Signatur von OpenPGP --]
[-- Type: application/pgp-signature, Size: 819 bytes --]