Author Topic: Major network problems - please help  (Read 4862 times)

jondecker76

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Major network problems - please help
« on: February 04, 2008, 05:09:09 am »
I have been running the same setup in my house for the last year - 4 Ubuntu computers (all the exact same, with same PCI cards, gfx cards, etc...)
connected to a Belkin WirelessG router.. My setup during this time has been:

DSL Modem -> Belkin WirelessG - >PC's

Pretty simple, and has worked well... But now I have been working on upgrading to a gigabit setup. The setup I want should be:

DSL Modem -> LMCE Core external NIC / LMCE Internal NIC-> D-Link Gigabit switch ->PC's, MD's and XBox 360

This sounds simple as well, but has turned out to be a nightmare.
Plugging my only wired Ubuntu PC into the gigabit switch yields nothing.. The networking Icon shows as disconnected. (but it has absolutely no problem connecting to the Belkin router) Doing reboots, enabling/disabling the network interface does nothing either. Its like its not even being seen by LMCE. In fact, even the light on the gigabit switch does not come on showing a connection on that port (though it blinks once in a while). If I boot the PC into Windows (it is a dual boot setup), then Window's has absolutely no problem connecting to the core.

So why am I haveing such a problem getting Ubuntu to connect to LMCE? I know the NIC and wiring are good, because windows connects to the core, and I also know that the NIC works in Ubuntu as I have used it for the last year, trouble free. The NIC is a gigabit card, and the gigabit switch supports 10/100 even if the card wasn't gigabit, so I'm highly doubting that it is a hardware issue. In fact, after 3 days of total frustration, I bought a brand new gigabit switch and ended up with the same results.

I guess its looking like the problem is in my Ubuntu box. Does anyone know what I should check next? Is there a way to reset my Ubuntu networking back to defaults? (I never changed anything, but the way it is acting makes me think something has changed somewhere - maybe a config file??)

thanks,

Jon

blackoper

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Re: Major network problems - please help
« Reply #1 on: February 04, 2008, 05:45:43 am »
have you tried swapping the nics in the admin page under networking? maybe your nics are reversed from the way you want to use them.
I'm confused as to what you are saying.. is the nic and the gigabit switch not showing any physical connection at all under linuxmce but is working fine under normal ubuntu?

jondecker76

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Re: Major network problems - please help
« Reply #2 on: February 04, 2008, 05:57:24 am »
Internal/External nics are correct - I can visit web pages by going into the Kubuntu desktop, as well as cover art downloads fine in LinuxMCE...

The problem is simply my Ubuntu computer will not get an IP address from the Core when connected to the switch (and the lights on the switch don't light up for that port)..  However, booting into windows will get an IP address, the lights will work on the switch, and everything works fine... 

Now if I connect my ethernet cable back up to my old router, then my Ubuntu computer has no problem obtaining an IP address from it.

So....  My Ubuntu box will not connect to my core when put through the switch (like its not seeing the DHCP services), but it can see the DHCP services of other hardware..

jondecker76

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Re: Major network problems - please help
« Reply #3 on: February 04, 2008, 06:04:30 am »
For example, I am connected right now as:

DSL Modem -> Core - > Gigabit switch - > PC

But I am booted into windows at the moment..  It obtained an IP address from the Core's DHCP, and now I have full networking. However, if I restart the PC and boot into Ubuntu, the networking Icon says "disconnected" and Internet does not work, the lights on the gigabit switch are off etc..

BUT... If i unplug my ethernet cable from the switch and plug it into any other device with DHCP services, then it gets an IP address as it should and everything will work..

This tells me that:
1) the NIC works under linux (hell, i've been using it for about a year under ubuntu)
2) The switch is good (did I mention this is the second switch I've bought now? same problem as the last one...)
3) Cabling etc.. is good (windows connects just fine, so will ubuntu if I connect it to anything else)
4) LinuxMCE's DHCP services are running (again, i can connect to it through windows)
5 My internal/external network cards are lined up right (I have internet access on my PC when booted into windows)

so where would the problem be?

royw

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Re: Major network problems - please help
« Reply #4 on: February 04, 2008, 06:13:32 am »
Try releasing the dhcp lease from windows (ipconnect /release) then rebooting into ubuntu.  What might be happening is the core's dhpcd is thinking that the mac address already has a lease so doesn't reissue one.

HTH,
Roy

jondecker76

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Re: Major network problems - please help
« Reply #5 on: February 04, 2008, 06:19:44 am »
how do I do that?

1audio

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Re: Major network problems - please help
« Reply #6 on: February 04, 2008, 08:13:43 am »
If the NIC's lights don't respond under Linux but do under Windows you may have a driver problem. The phy layer should work long before you have an IP address. Linux may not be turning on the NIC. Check the system status from a console (ifconfig etc.) make sure the NIC responds as appropriate. You may need to enable autoconfig of the interface.

colinjones

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Re: Major network problems - please help
« Reply #7 on: February 04, 2008, 08:30:46 am »
That's true - if you don't even have a "link" light on the switch, then it is highly likely that the ethernet hasn't even connected so you have no chance of getting an IP address. As 1audio says, most likely a driver problem - I would guess that it isn't autonegotiating 1G or the duplex setting.

Try:

sudo ethtool ethX  (where you put in 0 or 1, etc instead of X)

This will show you your ethernet interface statuses. The last line should say "Link detected: yes". If not then it hasn't even autoneg'd the right speed and duplex. Either driver issue, or config of that driver - can't help you with that as I am not a Linux person, but there are plenty of others here that will no doubt chime in.

Also, try sudo ifconfig -a on one of the lines at the beginning it should say "UP" that will indicate whether the TCP/IP stack is actually operational on that ethernet interface even if it hasn't got an IP address. My guess is you will find that the link is not even detected. Fix that first then you should see both UP and a valid IP address after, say, 10 seconds....

Col

jondecker76

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Re: Major network problems - please help
« Reply #8 on: February 04, 2008, 04:41:58 pm »
Ok, i have ran the suggested commands:

ifconfig
Code: [Select]
jondecker76@studio-desktop:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:18:F8:08:F8:6E 
          inet addr:192.168.2.4  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::218:f8ff:fe08:f86e/64 Scope:Link
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:1399 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1492 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1186130 (1.1 MB)  TX bytes:282275 (275.6 KB)
          Interrupt:20 Base address:0x8f00

lo        Link encap:Local Loopback 
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:70 errors:0 dropped:0 overruns:0 frame:0
          TX packets:70 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:5448 (5.3 KB)  TX bytes:5448 (5.3 KB)


sudo ethtool eth0
Code: [Select]
jondecker76@studio-desktop:~$ sudo ethtool eth0
[sudo] password for jondecker76:
Settings for eth0:
        Supported ports: [ TP ]
        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: Half
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        Supports Wake-on: pumbg
        Wake-on: g
        Current message level: 0x00000033 (51)
        Link detected: no



sudo ifconfig -a
Code: [Select]
jondecker76@studio-desktop:~$ sudo ifconfig -a
eth0      Link encap:Ethernet  HWaddr 00:18:F8:08:F8:6E 
          inet addr:192.168.2.4  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::218:f8ff:fe08:f86e/64 Scope:Link
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:1399 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1492 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1186130 (1.1 MB)  TX bytes:282275 (275.6 KB)
          Interrupt:20 Base address:0x8f00

lo        Link encap:Local Loopback 
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:70 errors:0 dropped:0 overruns:0 frame:0
          TX packets:70 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:5448 (5.3 KB)  TX bytes:5448 (5.3 KB)



The ethernet adapter is a Linksys EG1032 version 3

After some more research, I found this:
http://www.linuxcompatible.org/Linksys_Gigabit_Network_Adapter_EG1032_v3_c12430.html

So I guess these cards do have a driver problem that lets them work at 100 but bomb out at gigabit...

Can anyone recommend a good gigabit NIC that is linux compatible that they would have at Office Max?

blackoper

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Re: Major network problems - please help
« Reply #9 on: February 04, 2008, 05:46:31 pm »
I just bought a zonet pci-e gigabit card ZEN3320E from newegg for $20 a couple weeks back and it works great in kubuntu 7.10. Also I have a realtek pci gigabit card that works well. The best gigabit card I have is an Intel based chipset. You may want to ebay one and you will be all set there. One thing you want to do is avoid all Marvel chipsets as they are buggy in my experience and freeze up randomly. Also you want to get card that's linux driver doesn't need to have any custom kernel compilation done. Check out the website of the store in question and then lookup the chipsets of what you find in regard to linux compatibility

colinjones

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Re: Major network problems - please help
« Reply #10 on: February 04, 2008, 11:42:17 pm »
jon - I'm assuming from this that you only have a single NIC? It isn't creating a second sub-interface on that NIC as it should. The reason appears to be because your autonegotiation is failing.

Look - it says link detected:no and more importantly, it has failed back to 100M/HALF duplex. Sure sign of autoneg failure, and it is highly likely that your Gb switch simply can't connect to it causing this situation, or because of this situation.

Autoneg is turned on - assuming you will be connecting all Gb devices, I would suggest finding out how to force the NIC driver to 1Gb/Full duplex rather than let it autoneg the interface. Some manuf. autonegs are incompatible. Maybe your Windows machine is automatically setting it to "forced". Don't know where the config is for NIC drivers in Linux, maybe someone else can point you.

jondecker76

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Re: Major network problems - please help (*Solved*)
« Reply #11 on: February 05, 2008, 12:52:56 am »

I ordered an new gigabit card from newegg today - the one I was using has driver problems in linux when connected to a gigabit network. (I never noticed this problem in the year or so I used it, because I was on a 100Mbit network)

again, thanks for all the help