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Maxo
Your tax dollars at work.
Premium,VIP
join:2002-11-04
Tallahassee, FL

Random network issues

I've been working an issue for a client that has me stumped.
She was on Ubuntu 11.04 and upgraded to 12.04. Now she intermittently cannot access the Internet. Her network connection to her router doesn't disconnect, but any attempt to do anything on the Internet times out. After a while it work, then go back out after a while.
She has a small partition with Windows XP that connects to the Internet without issue, which is what she is using for right now.
I reinstalled Ubuntu 12.04 64-bit from scratch and the problem is still showing itself. In fact, during the first step of the install where it checks for Internet access it reported it could not connect.
She always has the addres 10.0.0.2 from her router. When the connections are failing tracepath show the request never getting past 10.0.0.1.
Given that this all work in Windows, and worked on Ubuntu 11.04 I am led to believe there's an issue somewhere in 12.04, but I'm not sure, at this point, what can be done about it. My only course of action I can come up from here is putting a new NIC in her machine.
Does anyone have any further ideas?
--
"Padre, nobody said war was fun now bowl!" - Sherman T Potter

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graysonf
Premium,MVM
join:1999-07-16
Fort Lauderdale, FL
kudos:2

I would statically assign an IP address, gateway, and DNS server(s) rather than use DHCP to obtain these and see what happens.

Is there more than one NIC in the machine?



Maxo
Your tax dollars at work.
Premium,VIP
join:2002-11-04
Tallahassee, FL

said by graysonf:

Is there more than one NIC in the machine?

There's only one NIC. I am statically assigning the DNS. I have noticed that at times the domain-name resolution is failing, and at other times the domain name resolves but the connection is still failing.
I'll try statically assigning the lot.
I'm also thinking of installing linux-generic-lts-quantal. Perhaps there's a module issue with this kernel and her NIC.
--
"Padre, nobody said war was fun now bowl!" - Sherman T Potter

»maxolasersquad.com/

»maxolasersquad.blogspot.com

»www.facebook.com/maxolasersquad

pablo
MVM
join:2003-06-23
kudos:1
reply to Maxo

said by Maxo:

Does anyone have any further ideas?

Hi Maxo See Profile,

When the connection is lost, are the NIC link lights lit? Have you tried connecting to a different port on the router? Could you add a new switch to act as a bridge between the router and the NIC? Have you tried a different NIC?

On the router, can you run a tcpdump?

I'm not a networking gawd unlike koitsu See Profile so perhaps he can chime in if he has the spare cycles.

-pablo
--
openSUSE 12.2/KDE 4.x
ISP: TekSavvy Bonded DSL; backhauled via a 6KM wireless link
Assorted goodies: »pablo.blog.blueoakdb.com


Maxo
Your tax dollars at work.
Premium,VIP
join:2002-11-04
Tallahassee, FL

Given that the issue does not appear on Windows, or an older version of Ubuntu, I did not troubleshoot the router at all. Also, limited testing with my laptop running Ubuntu 12.10 did not show any problems. Given that connectivity to the router was never lost I did not troubleshoot any hardware connectivity problems except I did unplug the network cable and plug it back in.



NS4683

join:2000-08-25
South Amboy, NJ
kudos:1
reply to Maxo

Do you notice anything in the logs? Which network card and kernel driver is being used?



Maxo
Your tax dollars at work.
Premium,VIP
join:2002-11-04
Tallahassee, FL

said by NS4683:

Do you notice anything in the logs? Which network card and kernel driver is being used?

I'm not sure which logs I should check. I'm just using the stock Ubuntu kernel.
Unfortunately I did not grep lspci for the card. I'll try to get that information.

pablo
MVM
join:2003-06-23
kudos:1
reply to Maxo

So, you're not going to run any of the tests I suggested? !

Sometimes it's easier to just do than to mind-trip over it ... I've learned some interesting things by abandoning my logic/understanding.

Good luck!

Cheers,
-pablo
--
openSUSE 12.2/KDE 4.x
ISP: TekSavvy Bonded DSL; backhauled via a 6KM wireless link
Assorted goodies: »pablo.blog.blueoakdb.com



Maxo
Your tax dollars at work.
Premium,VIP
join:2002-11-04
Tallahassee, FL
reply to Maxo

I e-mailed her friend, a common acquantaince, and asked him to run `lspci | grep 'Ethernet'` to which he responded.

I already know that. It's a Realtek RTL8111/8168B PCI Express Gigabit
Ethernet controller (rev. 03).

After you said it might be the network card, I realized immediately
with 95% certainty that that was it. I immediately remembered reading an article by someone complaining that the 3.? kernel removed some of the drivers for older hardware, frustrating a contingent with those older hardware devices. Remember that the tech who built her computer tried to save her as much money as possible and, in doing so, used an old NIC. So I got into Ubuntu and looked up the network card, wrote its specs down, then looked up troubles with it in 12.04. Voila! I got a Linux Mint forum web page that appeared to give the fix for it and printed it. Just now I looked up a slightly different search string and got a number of Ubuntu forum pages that appear to give the solution. I left the page I printed at her house and so can't compare it with these, but the solutions look about the same.

I'll post back when/if there is resolution.
--
"Padre, nobody said war was fun now bowl!" - Sherman T Potter

»maxolasersquad.com/

»maxolasersquad.blogspot.com

»www.facebook.com/maxolasersquad

pablo
MVM
join:2003-06-23
kudos:1
reply to pablo

said by pablo:

said by Maxo:

Does anyone have any further ideas?

Have you tried a different NIC?

.... and so it goes.


Maxo
Your tax dollars at work.
Premium,VIP
join:2002-11-04
Tallahassee, FL

said by pablo :

said by Maxo :

My only course of action I can come up from here is putting a new NIC in her machine.

Have you tried a different NIC?

Touché.
I'm guessing that the issue is the one reported at »askubuntu.com/questions/169457/r···-link-wi which suggest running the following.

sudo -s
nano /etc/initramfs-tools/modules --- added r8168 (saved)
update-initramfs -v -u -k `uname -r`

I'll report back when I hear more.
--
"Padre, nobody said war was fun now bowl!" - Sherman T Potter

»maxolasersquad.com/

»maxolasersquad.blogspot.com

»www.facebook.com/maxolasersquad

pablo
MVM
join:2003-06-23
kudos:1

said by Maxo:

said by pablo :

said by Maxo :

My only course of action I can come up from here is putting a new NIC in her machine.

Have you tried a different NIC?

Touche

Hi Maxo See Profile,

As you've figured out, it's the device driver for the NIC. It could have been the Linux device driver didn't like the router hardware etc. This is why I made the recommendation.

With NIC's so cheap, this is also why I suggested trying a different NIC. It takes all of two minutes to swap in a NIC.

This is why I was saying that at times, it's easier to simply try some different techniques, try something/anything, /different/.

The key is to only change one variable at a time /or/ to track what's been changed so you can revert/identify the culprit.

Cheers,
-pablo
--
openSUSE 12.2/KDE 4.x
ISP: TekSavvy Bonded DSL; backhauled via a 6KM wireless link
Assorted goodies: »pablo.blog.blueoakdb.com