I have installed Linux CentOS 5.5. During installation, I configured the LAN driver and gave it an IP address. After installation, I checked the network connection but it shows "not connected".

I then tried to enable dhcp (from broadband) but system-config-network shows

Determining IP information for eth0... failed; no link present. Check cable" 

I checked the cable and everything is OK with it. I then added

return 1;

to /etc/sysconfig/network-scripts/ifcfg-eth0 but system-config-network still shows the same message.

I have checked service NetworkManager status and service network status all is fine but I still can't connect to the network.

  • Does the output of dmesg or /var/log/messages show anything pertaining to the detection of the hardware for this NIC? – slm Oct 21 '13 at 17:59
  • can you tell us what your NIC is, and which driver it is (or not) using? – MariusMatutiae Oct 21 '13 at 19:12
  • @ MariusMatutiae I don't know what exactly my NIC is, It is HCL core i3 machine with inbuilt NIC – Abhishek Sharma Oct 24 '13 at 10:52
  • @ slm On dmseg it shows r8169: eth0: link down ; r8169: eth0: unknown chipset (mac_version=1); r8169: eth0: link down; ADDRCONF(NETDEV_UP): eth0: link is not ready; r8169: eth0: link down – Abhishek Sharma Oct 24 '13 at 10:55

Just try mii-tool to see if your cable has a signal:

user1@c55:~$ sudo mii-tool
eth0: negotiated 100baseTx-FD flow-control, link ok

Another way is using the toolethtool, for debugging NIC (network ethernet card) problems.

| improve this answer | |
  • Thanks for help. I have used mii-tool. it shows SIOCGMIIPHY on 'eth0' failed: Operation not supported no MII iterfaces found – Abhishek Sharma Oct 23 '13 at 11:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.