Re: Help! Slug takes down my network ...

it seems real strange that if the computer could not see anything with
ethereal over the switch it was still affected. I think the theory of the
slug taking over the gateway ip address somehow is probably close.

when the trouble occurs, can other machines still see each other ?

There is another thing I have had trouble with in the past - bad network
cables - if the cables were wired in the wall to plates, or hand made
cables, there is a chance someone made them with the wrong pairing.
Usually this works at 10mb/sec, but not at 100mb/sec depending on the
cable length. Having devices trying to autonegotiate speed just results in
error packets and endless retries of a tiny bit of traffic that looks like
a ton of activity with no useful result. Try a different cable, or swap
them around and see if the problem changes or goes away. These are weird
problems since they sometimes appear to work for a while and then some
factor such as temperature or even just moving the cable sets them off and
they become weirdly intermittant. Have a close look at your switch and see
if it is flickering from 10 to 100 when the problem is going on.






>
> Thanks for the reply Jon. Slug is configured with a
> fixed IP address. I did run ethereal from one of my
> computers, but since my router has 4 switched ports,
> ethereal couldn't see the packets the Slug was
> sending. As I said in my initial email, I did see in
> ethereal that my router was ignoring ARP requests for
> the router IP address while the flooding was going on.
> I have two network hubs but both are switches and
> wouldn't allow me to sniff the packets the Slug is
> sending. I guess I could go buy a simple hub or even a
> cross-over cable to see what the packets are, even
> though I'd rather not put more money into this
> project.
>
> If I decide to break down and buy a hub, I'll let you
> know what kind of packets I see.
>
> Thanks
>
> Nathan
> --- Jon Pounder <jonp-PJXPO3/4scSsTnJN9+BGXg@xxxxxxxxxxxxxxxx> wrote:
>
> ---------------------------------
>
>
> I would grab something like ethereal and sniff the
> network while this is
> happening. Just because the network light is flashing
> does not mean the
> network is saturated. That will tell you what is
> actually going on so you
> know where to look to fix it.
>
> I would suspect a couple of things but there could be
> more:
>
> - networking is just broken and it is flooding the
> network with bad
> packets (jabber), if you have a switch or a good hub,
> it might be able to
> partition things on its own and isolate the trouble.
>
> - my most likely guess is that somehow the slug has
> grabbed a dhcp address
> it shouldn't have, like the gateway, and the two nics
> are just fighting
> over the ip. This causes the other computers not to
> work since they have
> no gateway.
>
> Even though I use dhcp for stuff like this, I still
> hard code the mac
> addresses of the devices so they get specific ip
> addresses, but I can
> manage them without going to every device and changing
> it.
>
>
>>
>>
>> Well I thought I finally had my Slug under control.
> With the help of
>> these Yahoo groups I've figured out how to clear
> hung backup jobs
>> and I've been successfully backing up three
> computers on my home
>> network. I got ssh and sudo installed for secure
> root access. I got
>> ntpclient running per the HOWTO so it keeps good
> time.
>>
>> Then this morning my wife complained she could not
> print from her
>> laptop. I verified this and also noticed she could
> no longer access
>> the internet nor even bring up a Windows Explorer
> window.
>>
>> On a whim I pull out the Ethernet cable from my
> Slug. All of a
>> sudden her computer works again, printing and
> surfing. I plug the
>> Slug back into the network and it stops. I notice
> while the Slug is
>> plugged in the network light on it is blinking
> constantly and so is
>> the light for that port on my SMC 7004AWBR wireless
> router. I also
>> notice none of the other computers in the house
> work.
>>
>> An Ethereal trace from one computer shows my router
> has stopped
>> responding to ARP requests. If I unplug the Slug,
> ARPs work again.
>>
>> The Slug is running Unslung 3.18 and it does respond
> to the power
>> button and shuts down. If I reboot it without the
> external drive
>> attached it seems to boot up but immediately starts
> flooding the
>> network again.
>>
>> The previous night I had made the /unslung changes
> to get ntpclient
>> to work per the HOWTO. I rebooted then and verified
> everything
>> worked. I also disabled UPnP that night. My backup
> jobs all ran fine
>> from midnight to 3 am, while I was alseep, which I
> verified by
>> checking the backup log through the Admin web GUI
> about 7 am.
>>
>> So in between 7 am and 9 am the Slug started this
> flooding behavior
>> all by itself and has not recovered.
>>
>> Any ideas what could be going on? I've spend many
> hours in the wiki
>> and searching forums to get this thing working in
> the first place as
>> a backup device. It is frustrating that it only
> worked well for a
>> few days.
>>
>> Since it is flooding the network I assume I can't
> use the Linksys
>> Setup to flash it back to factory. Is there anything
> I could do at
>> the Redboot prompt to recover? What about the
> Sercomm utility?
>>
>> Will this be a stable backup device for my network
> in the longterm?
>> It is nice that it is a cool little Linux box to
> play with, but I
>> did buy it to do an important job.
>>
>> Thanks for any advice.
>>
>> Nathan
>>
>>
>>
>>
>>
>> [ Moderator Note: All static information is slowly
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>> Yahoo! Groups Links
>>
>>
>>
>>
>>
>>
>>
>>
>
>
> Jon Pounder
>
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Jon Pounder

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