Dear all, I find out of a sudden my?Network?manager cannot connect to the Internet. My OS is Centos 6.7, and the version of?Network?manager is Applet 0.8.1. When clinking the ?Network?manager icon at the upper right conner at the Desktop of my compuer, I can see in the?pop-up?manu that there are two network ?cards (Intel 82573E Gigabit Ethernet Controller (Copper) and Intel 82573L Gigabit Ethernet Controller)?but?only one link (System eth1) available. Usually when clicking the "System eth1" the Internet connection would be established. However from this morning?clicking the "System eth1" only gives connect failure information. I don't know whether this is caused by intalling a large software package (ambertool 16 ) which requires many updates in my system yesterday. ? ?But when I give "ifconfig" command in a gnome terminal, the output information seems to be correct: [sunyp at localhost?Desktop]$?ifconfig??? eth0??????Link?encap:Ethernet??HWaddr?00:25:90:72:E2:86?? ??????????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:16?Memory:faee0000-faf00000? eth1??????Link?encap:Ethernet??HWaddr?00:25:90:72:E2:87?? ??????????inet6?addr:?fe80::225:90ff:fe72:e287/64?Scope:Link ??????????UP?BROADCAST?RUNNING?MULTICAST??MTU:1500??Metric:1 ??????????RX?packets:49?errors:0?dropped:0?overruns:0?frame:0 ??????????TX?packets:11?errors:0?dropped:0?overruns:0?carrier:0 ??????????collisions:0?txqueuelen:1000? ??????????RX?bytes:16386?(16.0?KiB)??TX?bytes:3038?(2.9?KiB) ??????????Interrupt:17?Memory:fafe0000-fb000000? 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:65536??Metric:1 ??????????RX?packets:90?errors:0?dropped:0?overruns:0?frame:0 ??????????TX?packets:90?errors:0?dropped:0?overruns:0?carrier:0 ??????????collisions:0?txqueuelen:0? ??????????RX?bytes:6737?(6.5?KiB)??TX?bytes:6737?(6.5?KiB) What I can do now? Could anyone help me with this problem? Best regards. Yeping Sun
Earl A Ramirez
2016-Sep-03 10:37 UTC
[CentOS] Network manager cannot connet to the Internet
What is the output of ip route show, can you ping your gateway, first see if you can ping your default gateway and if you can't you will have to check the device that your are connecting to. -- Kind Regards Earl Ramirez
Hi,?Earl, Thank you very much for your prompt response.There is no output for "ip route"I don't know what is my default gateway and how to check it??And how to?check?the?device?that I am connecting?to? Best regards. Yeping------------------------------------------------------------------From:Earl A Ramirez <earlaramirez at gmail.com>Time:2016 Sep 3 (Sat) 18:38To:CentOS mailing list <centos at centos.org>Subject:Re: [CentOS] Network manager cannot connet to the Internet What?is?the?output?of?ip?route?show,?can?you?ping?your?gateway,?first?see if?you?can?ping?your?default?gateway?and?if?you?can't?you?will?have?to check?the?device?that?your?are?connecting?to. --? Kind?Regards Earl?Ramirez _______________________________________________ CentOS?mailing?list CentOS at centos.org https://lists.centos.org/mailman/listinfo/centos
Gordon Messmer
2016-Sep-06 22:39 UTC
[CentOS] Network manager cannot connet to the Internet
On 09/03/2016 03:08 AM, sunyeping wrote:> But when I give "ifconfig" command in a gnome terminal, the output information seems to be correct: > > [sunyp at localhost Desktop]$ ifconfig > ... > eth1 Link encap:Ethernet HWaddr 00:25:90:72:E2:87 > inet6 addr: fe80::225:90ff:fe72:e287/64 Scope:Link > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:49 errors:0 dropped:0 overruns:0 frame:0 > TX packets:11 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:16386 (16.0 KiB) TX bytes:3038 (2.9 KiB) > Interrupt:17 Memory:fafe0000-fb000000You don't have any valid IPv4 or IPv6 addresses. Normally those things are provided by your router. Check your cabling first. Then check your router's logs to see if it's getting DHCP requests from your desktop.