[PLUG] Network issues

Denis Heidtmann denis.heidtmann at gmail.com
Thu Jan 21 03:21:25 UTC 2010


On Wed, Jan 20, 2010 at 5:36 PM, Mike Connors <mconnors1 at gmail.com> wrote:
> drew wymore wrote:
>> I think route -n is what I was thinking of. So disregard what I wrote.
>> Ok .. so next thing I'm thinking of is that the PK5000 according to
>> the docs I pulled up is 10/100BaseT and since you have a Gigabit NIC,
>> I'm starting to lean towards a negotiation error of some sort or too
>> many errored frames.
> Auto-neg probs would certainly come more into play during bootup. If in fact
> the PK5000 supports only 10/100BaseT and your onboard NIC is 1000BaseT then I
> would definitely try disabling auto-neg and forcing speed/dup on your NIC.
>
> Here's a good write-up on how to use ethtool to do it.
>
> http://www.cyberciti.biz/tips/howto-linux-add-ethtool-duplex-settings-permanent.html
>
> I wonder also if you can't replicate the problem by stopping and starting the
> networking daemon which is akin to rebooting as far as the NIC and tcp/ip stack is concerned?
>
> /etc/init.d/network restart
>
> Because if you can this would narrow the problem down to network connection
> initiation, which points to auto-neg probs...
>

sudo ethtool eth0

Settings for eth0:
	Supported ports: [ MII ]
	Supported link modes:   10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Full
	Supports auto-negotiation: Yes
	Advertised link modes:  10baseT/Half 10baseT/Full
	                        100baseT/Half 100baseT/Full
	                        1000baseT/Full
	Advertised auto-negotiation: Yes
	Speed: 100Mb/s
	Duplex: Full
	Port: MII
	PHYAD: 3
	Transceiver: external
	Auto-negotiation: on
	Supports Wake-on: g
	Wake-on: d
	Link detected: yes

Notice the 1000baseT/full entry under Advertised link modes.  This
entry is present ONLY when the network is functioning.  It is absent
when the network is in its failed mode.  Does this support the idea
that negotiation is a likely source of the problem?

I like the idea of trying network restart.  However, I have yet to
have a change in state (bad->good or good->bad) without powering off
the computer.   It would be ideal if I could set up a little script to
performing network restart then ping the modem, then repeat.  That way
I could exercise the initiation much faster than booting.  If no
failures are created, then it is on to powering the desktop off.

-Denis



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