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Amir Tal | 1 Feb 2003 13:09

Re: Dead Network

On Saturday 01 February 2003 12:29, Boris Ratner wrote:
> On ׳©', 2003-02-01 at 10:32, Shoshannah Forbes wrote:
> > Every time the computer is left to manage it's own business (for
> > example, stay on during the night), it looses it's network.
> >
> > System setup:
> > Dell inspiron 7000 laptop
> > Mandrake 9
> > 10/100 3com PCMCIA Network card
> >
> > As far as I can tell, APM is off.
> > I can not connect to anything- ping to the dhcp server (the ADSL
> > router) doesn't work either.
> > The light on the Network card is on- but it is on the 10 MB instead of
> > on the 100 MB as it should.
> >
> > any ideas?
> >
> > Thanks
>
> Try checking that the cable is ok. Just replace it by another one.
> You can also check it by connecting to another computer with crossed
> cable.

if the cable was faulty, the network would not work in any case, so this is 
probably not the cause. it has something to do with the network management of 
the system (software) and not hardware.
what are the logs showing ? maybe something causes the network module to 
unload ? do "lsmod |grep modulename" in the morning, and see if the module is 
still loaded.

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Boris Ratner | 1 Feb 2003 14:31

Re: Dead Network

On ש', 2003-02-01 at 14:09, Amir Tal wrote:
> On Saturday 01 February 2003 12:29, Boris Ratner wrote:
> > On ׳©', 2003-02-01 at 10:32, Shoshannah Forbes wrote:
> > > Every time the computer is left to manage it's own business (for
> > > example, stay on during the night), it looses it's network.
> > >
> > > System setup:
> > > Dell inspiron 7000 laptop
> > > Mandrake 9
> > > 10/100 3com PCMCIA Network card
> > >
> > > As far as I can tell, APM is off.
> > > I can not connect to anything- ping to the dhcp server (the ADSL
> > > router) doesn't work either.
> > > The light on the Network card is on- but it is on the 10 MB instead of
> > > on the 100 MB as it should.
> > >
> > > any ideas?
> > >
> > > Thanks
> >
> > Try checking that the cable is ok. Just replace it by another one.
> > You can also check it by connecting to another computer with crossed
> > cable.
Try doing this by the book:
1. ping local loopback "ping 127.0.0.1" if successful
2. ping your nic's ip address (ifconfig) if you don't have an address 
(dhcp server unreachable) set one 
'ifconfig eth0 10.0.0.1 nemask 255.255.255.0'
then ping 10.0.0.1

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Tzafrir Cohen | 1 Feb 2003 20:51

Re: Dead Network

On Sat, 1 Feb 2003, Boris Ratner wrote:

> Try doing this by the book:
> 1. ping local loopback "ping 127.0.0.1" if successful
> 2. ping your nic's ip address (ifconfig) if you don't have an address
> (dhcp server unreachable) set one
> 'ifconfig eth0 10.0.0.1 nemask 255.255.255.0'
> then ping 10.0.0.1
> if both 1 and 2 worked fine the software is good.
> 3. ping another box on the same subnet to make sure.

(1) and (2) are almost equivalent (if the network interface is up).

A ping to any local interface will not go through that interface and loop
back. (2) won't tell you anything about the machine's network settings. I
dare say that it will always work (unless "eth0" doesn't exist)

Anyway, the original question was (if I understand it correctly): what
caused the connection to go down in the first place?

A number of possible reasons:

- eth10/100 conflicts (as suggested by Shahar)

- inavailability of the dhcp server . Though at least isc's standard dhcp
  client remains active and polls the last known address of the dhcp
  server every once in a while in such a case.

--

-- 
Tzafrir Cohen

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