Suddenly, Cable Unplugged ?

Questions about Wi-Fi and other network devices, file sharing, firewalls, connection sharing etc
Forum rules
Before you post read how to get help. Topics in this forum are automatically closed 6 months after creation.
Locked
sandt1g3r

Suddenly, Cable Unplugged ?

Post by sandt1g3r »

I am using Mint 13 x64 w/ Cinnamon on my laptop that has a realtek nic (uses r8169). Both cable and wireless connections were working fine at my home, but now I am in my college and my wired connection always shows cable unplugged (and I dont have wireless here). Cable was working fine at college too before I left for home a few days ago, and it still is in Windows.

I have tried the following:
Manually setting the link speed to 100Full Deplex using mii-tool
Removing battery for a few minutes etc.

I read the fix about manually setting MAC address of the device using ifconfig, however that does not seem to be the problem because eth0 is showing a MAC address.

Thanks in advance
Last edited by LockBot on Wed Dec 28, 2022 7:16 am, edited 1 time in total.
Reason: Topic automatically closed 6 months after creation. New replies are no longer allowed.
sandt1g3r

Re: Suddenly, Cable Unplugged ?

Post by sandt1g3r »

^Could you be more elaborate ?

BTW, here's more info to help you help me :)

Code: Select all

eth0      Link encap:Ethernet  HWaddr 14:fe:b5:XX:XX:XX  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:50 Base address:0x4000

Code: Select all

        Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06)
	Subsystem: Dell Device 04b6
	Flags: bus master, fast devsel, latency 0, IRQ 50
	I/O ports at 2000 [size=256]
	Memory at f1804000 (64-bit, prefetchable) [size=4K]
	Memory at f1800000 (64-bit, prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: r8169
	Kernel modules: r8169

I am currently running 3.2.0.34 linux generic kernel.

Thanks for any help (and happy new year)
sandt1g3r

Re: Suddenly, Cable Unplugged ?

Post by sandt1g3r »

Ok, the problem seems to be fixed. I read somewhere that Windows driver shuts down the Realtek NIC when Windows boots down and r8169 module is not able to detect this, so I held the power key in Windows to abruptly turn off the laptop, and then the NIC worked. I dont know if there's credit to the theory but ...whatever works :P
billmc

Re: Suddenly, Cable Unplugged ?

Post by billmc »

Ok, the problem seems to be fixed. I read somewhere that Windows driver shuts down the Realtek NIC when Windows boots down and r8169 module is not able to detect this
Personally, I wouldn't put much stock in that. When you reboot, the process of "rebooting" sends a "clear" signal, so to speak, throughout your hardware. What windows did or didn't do, does not affect what another operating system will do.
eth0 Link encap:Ethernet HWaddr 14:fe:b5:XX:XX:XX
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:50 Base address:0x4000
This appears to be the output of the ifconfig command. It does not show an IP address assigned to eth0. That's why you weren't able to get outside your box. Seeing as how, after rebooting, you're able to communicate; I'll make a guess and say that somehow, the first time network manager got "hosed" and the second time it worked as advertised.

To see the difference, compare this ifconfig output to the output of -> sudo ifconfig eth0
once you're connected. You should be able to see the address I was refering to.
sandt1g3r

Re: Suddenly, Cable Unplugged ?

Post by sandt1g3r »

You are right billmc. Moreover the cold reboot solution did not work when I experienced this problem again today. This bug seems to be an present since a long time. After trying a lot of stuff I ended up installing the r8168 kernel module instead of r8169 which is used by default. Here is the step by step procedure I followed -

Download driver from here

Code: Select all

tar -xvf r8168-XX.tar.bz2
sudo rmmod r8169
cd r8168-XX
sudo ./autorun.sh
Thats it. The autorun script took care of building the module, modprobing and updating the initramfs and now it loads everytime instead of r8169, so I guess there's no need to blacklist it.

Code: Select all

06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06)
	Subsystem: Dell Device 04b6
	Flags: bus master, fast devsel, latency 0, IRQ 50
	I/O ports at 2000 [size=256]
	Memory at f1804000 (64-bit, prefetchable) [size=4K]
	Memory at f1800000 (64-bit, prefetchable) [size=16K]
	Capabilities: <access denied>
	Kernel driver in use: r8168
	Kernel modules: r8168
Locked

Return to “Networking”