Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: ethernet wont connect

  1. #1
    Join Date
    Sep 2021
    Beans
    4

    ethernet wont connect

    i am new to Ubuntu and need help, i can connect to internet with wifi adapter but ethernet cable doesnt work. result of nmcli is
    Code:
    enp2s0: connecting (getting IP configuration) to Profile 1
            "Realtek RTL8111/8168/8411"
            ethernet (r8168), F4:4D:30:AD:8B:65, hw, mtu 1500
    
    lo: unmanaged
            "lo"
            loopback (unknown), 00:00:00:00:00:00, sw, mtu 65536

  2. #2
    Join Date
    Mar 2010
    Location
    Squidbilly-Land
    Beans
    Hidden!
    Distro
    Ubuntu

    Re: ethernet wont connect

    a) which version and release of Ubuntu?

    b) which kernel?

    c) exactly which version of the NIC? Realtek has a bad habit of using the same name across 50 different hardware configs. They change the "version" of the card to denote something changed. Often, that tiny version difference is what changes the driver needed.

    For example, these commands would be how I got the needed information:
    Code:
    lsb_release -a
    uname -a
    lshw -C network
    And my answers are:
    a) Description: Ubuntu 18.04.6 LTS
    b) 5.4.0-84-generic
    c)
    Code:
      *-network DISABLED        
           description: Ethernet interface
           product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
           vendor: Realtek Semiconductor Co., Ltd.
           physical id: 0
           bus info: pci@0000:02:00.0
           logical name: eth0
           version: 0c
           serial: fc:aa:14:a7:aa:aa
           size: 10Mbit/s
           capacity: 1Gbit/s
           width: 64 bits
           clock: 33MHz
           capabilities: bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
           configuration: autonegotiation=on broadcast=yes driver=r8168 driverversion=8.045.08-NAPI duplex=half latency=0 link=no multicast=yes port=twisted pair speed=10Mbit/s
           resources: irq:31 ioport:e000(size=256) memory:f7b00000-f7b00fff memory:f0000000-f0003fff
    I'm not using the Realtek NIC in that machine for a number of reasons. It worked fine for about 4 yrs, then started dropping packets so I disabled it and started using a different NIC instead. I've had a 4-port Intel PRO/1000 NIC to install into the machine for a few years, but just haven't gotten around to doing that yet.

    I'm not a fan of Realtek stuff and go out of my way to avoid their network stuff in all my newer computers. I just don't need the hassle.

  3. #3
    Join Date
    Sep 2021
    Beans
    4

    Re: ethernet wont connect

    a) I am using Ubuntu 21.04 based Pop!_OS but unfortunately i cant register to Pop!_OS forum because of an error, so i need help from here.

    b) This is the output of uname -a
    Code:
     Linux yigit 5.13.0-7614-generic #14~1631647151~21.04~930e87c-Ubuntu SMP Fri Sep 17 00:24:58 UTC  x86_64 x86_64 x86_64 GNU/Linux
    c) Output of lshw -C network
    Code:
      *-network                 
           description: Ethernet interface
           product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
           vendor: Realtek Semiconductor Co., Ltd.
           physical id: 0
           bus info: pci@0000:02:00.0
           logical name: enp2s0
           version: 15
           serial: f4:4d:30:ad:8b:65
           size: 1Gbit/s
           capacity: 1Gbit/s
           width: 64 bits
           clock: 33MHz
           capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
           configuration: autonegotiation=on broadcast=yes driver=r8168 driverversion=8.048.03-NAPI duplex=full latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s
           resources: irq:123 ioport:d000(size=256) memory:df104000-df104fff memory:df100000-df103fff
    And i noticed that when i reset the router, internet works but when i restart the computer the problem occurs again.
    Yes, this NIC might be problematic, I was only able to get it to work on windows easily.

  4. #4
    Join Date
    May 2014
    Location
    /home
    Beans
    9,612
    Distro
    Ubuntu 18.04 Bionic Beaver

    Re: ethernet wont connect

    Moved to Ubuntu/Debian based

  5. #5
    Join Date
    Mar 2010
    Location
    Squidbilly-Land
    Beans
    Hidden!
    Distro
    Ubuntu

    Re: ethernet wont connect

    Quote Originally Posted by yigitus View Post
    a) I am using Ubuntu 21.04 based Pop!_OS but unfortunately i cant register to Pop!_OS forum because of an error, so i need help from here.
    I've never touched Pop.

    First, 21.04 isn't an LTS release, so expect issues, especially with new hardware.

    5.13.x is a VERY NEW kernel. I don't know **any** Ubuntu using it yet. I think the most current is 5.11.x. My 20.04 kernel is 5.4.x and with extra effort by loading the HWE kernel, Ubuntu users can get 5.11.x kernels.

    Don't make the mistake of confusing "new" for "better". When it comes to hardware support, that is seldom the answer on Linux. Most hardware vendors don't test with Linux at all, so it isn't surprising when hardware works on Windows. That's 90+% of the market, so why would they spend 50% of their development and testing budget on 5% of the users, especially for low-end devices? Hint: they don't.

    Realtek does make drivers for Linux, but their QC in the HW and SW has always seemed to be lacking from what I've seen. Lots of people have fine experiences with their hardware, so it isn't all bad.

    What would I do?
    I'd run the current LTS version of Pop with a 5.4.x kernel or older. The trick is to have the LTS and the right kernel.
    I'd search these forums for people who have realtek NICs with exactly the same version (15) of the NIC that you have and see what they did to solve the issue. Do that.

    Never confuse "new" with "better." That isn't how computers work. This applies to both hardware AND software.

  6. #6
    Join Date
    Jun 2007
    Location
    Macon, GA
    Beans
    552
    Distro
    Ubuntu 20.04 Focal Fossa

    Re: ethernet wont connect

    This is a major problem and it effects 21.04 itself, not the Debian version. One of my PCs gives essentially the same lists as reported above by yigitus. PC is duel boot with Windows 10 Pro. To get Ethernet on 21.04, I need to boot into Win 10 first. Shutdown PC and immediately restart and let it boot into 21.04. John

  7. #7
    Join Date
    Mar 2010
    Location
    Squidbilly-Land
    Beans
    Hidden!
    Distro
    Ubuntu

    Re: ethernet wont connect

    Quote Originally Posted by cigtoxdoc View Post
    This is a major problem and it effects 21.04 itself, not the Debian version. One of my PCs gives essentially the same lists as reported above by yigitus. PC is duel boot with Windows 10 Pro. To get Ethernet on 21.04, I need to boot into Win 10 first. Shutdown PC and immediately restart and let it boot into 21.04. John
    When booting Windows first, then a soft-reboot makes it work on Linux, that has been traced back to bad driver initialization. In C, we are supposed to initialize all variables to known values. That's easy:
    Code:
    int some_interger=0;
    But it is extremely common for programmers - all programmers - to be lazy and just use:
    Code:
    int some_interger;
    instead. Different compilers implement static allocation of variables differently. Some will zero out the entire DS first, so all variables are effectively zero. But others don't do anything and whatever the RAM had from prior use, by different programs on the system will hold random values.

    The first method will be optimized away by the compiler, if it isn't needed.
    The second may work fine or it may not. Just depends on the compiler and the settings for the compiler.

    I know of no fix other than to get the source code and fix all the uninitialized variables, recompile, then make fresh objects and drivers for each kernel version.

    Of course, the issue could be something completely different and setting all variables to known values can cause the driver to crash, since known is usually 0. You'd think that having a pointer set to a random location rather than 0 would be bad ... and it is, but it often doesn't crash. Instead, it returns bogus information and in a network driver that bogus information could be dropped because the packets would be out of order and re-assembly would fail - i.e. drop that single packet. Nobody would likely notice, since it had bogus information anyway.

    So ... how's your C coding? Can you get the source and fix it?

  8. #8
    Join Date
    Jun 2007
    Location
    Macon, GA
    Beans
    552
    Distro
    Ubuntu 20.04 Focal Fossa

    Re: ethernet wont connect

    Thank you, but not into C

    Motherboard is MSI CSM-B85M-P32

  9. #9
    Join Date
    Sep 2021
    Beans
    4

    Re: ethernet wont connect

    Thanks for the suggestions, i don't know much about drivers so i'll just try using an older ubuntu and kernel with LTS
    Last edited by yigitus; September 23rd, 2021 at 08:20 AM.

  10. #10
    Join Date
    Sep 2021
    Beans
    4

    Re: ethernet wont connect

    i installed Ubuntu 20.04, configured network settings manually and it worked.

Page 1 of 2 12 LastLast

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •