No wired network connection but wireless

Issues Related to Networking (Wired and Wireless)

Moderator: Moderators

No wired network connection but wireless

Postby Honeyman » Sun Jun 22, 2014 14:37

Hi all,

from time to time I have issues to establish a wired internet connection via the interface eth0, but at the same time I can connect via wireless. Currently this is happening while I am at my university, where I'd like to use the VPN connection over LAN which is much faster (glass fibre - 1000Mbit/s!!!! download).

Wired stopped working all of a sudden, no upgrades or anything.

I found this thread (https://forum.sabayon.org/viewtopic.php?f=52&t=31533), but still groping for a solution.

I hope these information are helpful for troubleshooting my issues:

Code: Select all
# ifconfig -a
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet6 fe80::a9e:1ff:fedd:db04  prefixlen 64  scopeid 0x20<link>
        ether 08:9e:01:dd:db:04  txqueuelen 1000  (Ethernet)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 260  bytes 99064 (96.7 KiB)
        TX errors 0  dropped 96 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 0  (Lokale Schleife)
        RX packets 43465  bytes 3732069 (3.5 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 43465  bytes 3732069 (3.5 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.242.124.3  netmask 255.0.0.0  broadcast 10.255.255.255
        inet6 fe80::4ad2:24ff:fe5d:f494  prefixlen 64  scopeid 0x20<link>
        ether 48:d2:24:5d:f4:94  txqueuelen 1000  (Ethernet)
        RX packets 1538144  bytes 2313548118 (2.1 GiB)
        RX errors 0  dropped 35  overruns 0  frame 0
        TX packets 671228  bytes 53166823 (50.7 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0



I cannot get a dynamic IP address via

Code: Select all
# dhclient eth0


Here is the status of network manager:

Code: Select all
systemctl status NetworkManager
NetworkManager.service - Network Manager
   Loaded: loaded (/usr/lib64/systemd/system/NetworkManager.service; enabled)
   Active: active (running) since Sun 2014-06-22 15:20:07 CEST; 9min ago
 Main PID: 10967 (NetworkManager)
   CGroup: /system.slice/NetworkManager.service
           ├─10967 /usr/sbin/NetworkManager --no-daemon
           ├─11103 /sbin/dhcpcd -B -K -L -G -c /usr/libexec/nm-dhcp-client.action -4 wlan0
           └─11373 /sbin/dhcpcd -B -K -L -G -c /usr/libexec/nm-dhcp-client.action -4 eth0

Jun 22 15:28:56 Sabayon-Aspire NetworkManager[10967]: <info> Activation (eth0) Stage 3 of 5 (IP Configure Start) started...
Jun 22 15:28:56 Sabayon-Aspire NetworkManager[10967]: <info> (eth0): device state change: config -> ip-config (reason 'none') [50 70 0]
Jun 22 15:28:56 Sabayon-Aspire NetworkManager[10967]: <info> Activation (eth0) Beginning DHCPv4 transaction (timeout in 45 seconds)
Jun 22 15:28:56 Sabayon-Aspire NetworkManager[10967]: <info> dhcpcd started with pid 11373
Jun 22 15:28:56 Sabayon-Aspire NetworkManager[10967]: <info> Activation (eth0) Stage 3 of 5 (IP Configure Start) complete.
Jun 22 15:28:56 Sabayon-Aspire dhcpcd[11373]: version 6.3.2 starting
Jun 22 15:28:56 Sabayon-Aspire dhcpcd[11373]: DUID 00:01:00:01:1b:2f:68:91:08:9e:01:dd:db:04
Jun 22 15:28:56 Sabayon-Aspire dhcpcd[11373]: eth0: IAID 01:dd:db:04
Jun 22 15:28:56 Sabayon-Aspire NetworkManager[10967]: <info> (eth0): DHCPv4 state changed nbi -> preinit
Jun 22 15:28:56 Sabayon-Aspire dhcpcd[11373]: eth0: soliciting a DHCP lease


I tried stopping the network manager and restarting it manually, which didn't help:
Code: Select all
# systemctl stop NetworkManager


Then:
Code: Select all
# ip link set up dev eth0

# dhclient eth0


Here is the configuration file for the wired interface

/etc/NetworkManager/system-connections/Kabelgebundene\ Verbindung\ 1

Code: Select all
[802-3-ethernet]
mac-address=08:9E:01:DD:DB:04

[connection]
id=Kabelgebundene Verbindung 1
uuid=7b847feb-86bc-41e2-a595-8f0d59c3ef65
type=802-3-ethernet
timestamp=1403436059

[ipv6]
method=ignore

[ipv4]
method=auto

I did not choose the name of the interface, apparently the German localization did that.


Thanks for your help and tell me, if some important information is still missing
Je me regarde pour me désoler,
je me compare pour me consoler

Maurice de Talleyrand
Honeyman
Growing Hen
 
Posts: 159
Joined: Sun Apr 08, 2012 2:25
Location: Berlin, Germany

Re: No wired network connection but wireless

Postby Fitzcarraldo » Tue Jun 24, 2014 15:24

Does Network Manager work with other wired networks? Is the problem only occurring with your university's wired network?
User avatar
Fitzcarraldo
Sagely Hen
 
Posts: 7978
Joined: Sat Mar 10, 2007 5:40
Location: United Kingdom

Re: No wired network connection but wireless

Postby Honeyman » Tue Jun 24, 2014 17:15

No, I'm having this problem at the university and at home. I guess somehow dhcp doesn't work too well with the wired network. The strange thing is, that this happenes sometimes and sometimes everything works well.
Je me regarde pour me désoler,
je me compare pour me consoler

Maurice de Talleyrand
Honeyman
Growing Hen
 
Posts: 159
Joined: Sun Apr 08, 2012 2:25
Location: Berlin, Germany

Re: No wired network connection but wireless

Postby Fitzcarraldo » Wed Jun 25, 2014 3:06

Network Manager in SL is built with USE="-dhclient dhcpcd", so it's using dhcpcd, not dhclient, as the DHCP client. See:

https://packages.sabayon.org/show/netwo ... -show-what

You can also see that it's using dhcpcd as the DHCP client from the output of the command "systemctl status NetworkManager" that you posted.

(BTW, back in February I had to start using dhcpcd with Network Manager instead of dhclient in my Gentoo installation, as I found that Network Manager stopped working with dhclient: http://forums.gentoo.org/viewtopic-t-983000.html ).

Normally you should not run the DHCP client yourself, as Network Manager takes care of all that.

You might find you get better results once SL uses the latest version of dhcpcd (6.4.0) rather than the version currently in the Entropy Weekly repository (6.3.2). I'm using 6.4.0 in Gentoo and it works fine, although I'm not using systemd so I don't know whether or not that is a factor in what you're seeing.

What do you have in the file /etc/resolv.conf?

Code: Select all
# cat /etc/resolv.conf
# Generated by resolvconf
domain home
nameserver 192.168.1.254

Try running dhcpcd in a Konsole/Terminal window to see what it outputs, although you shouldn't need to run it (or any other DHCP client such as dhclient), because Network Manager takes care of all that.

Code: Select all
# dhcpcd

I notice a difference between your file "/etc/NetworkManager/system-connections/Kabelgebundene\ Verbindung\ 1" and mine ("/etc/NetworkManager/system-connections/Wired\ connection\ 1"): instead of the line "timestamp=1403436059" after the line "type=802-3-ethernet", mine has the following line specifying my two Linux user accounts:

Code: Select all
permissions=user:fitzcarraldo:;user:aguirre:;

Also, what do you have in the file /etc/NetworkManager/NetworkManager.conf? Here is what I have in mine:

Code: Select all
[main]
plugins=keyfile

dhcp=dhcpcd

[ifnet]
managed=true
auto_refresh=false

[keyfile]
hostname=meshedgedx

I added the line "dhcp=dhcpcd" (and, IIRC, the line specifying the hostname). I also removed the reference to the obsolete plugin ifnet from "plugins=ifnet,keyfile".

Also, have you checked what the MTU is for your wired Ethernet adapter? I have had trouble connecting to wired or wireless networks due to different MTUs: see Why can’t I access a specific Web site?. You might like to disable ipv6 to see if that is having an effect. I edit /etc/modprobe.d/aliases.conf and uncomment the line "alias net-pf-10 off" in my Gentoo installation, but I don't know if that still works in SL these days, as there is a way to do it in systemd (https://wiki.archlinux.org/index.php/IPv6#Disable_IPv6).
User avatar
Fitzcarraldo
Sagely Hen
 
Posts: 7978
Joined: Sat Mar 10, 2007 5:40
Location: United Kingdom

Re: No wired network connection but wireless

Postby Honeyman » Wed Jun 25, 2014 10:10

Thanks for your elaborate reponse, you must have put in whole lot of effort and time.

The funny thing is, that since I posted my problem here, the issues seems to have gone away, at least for now.

Here is my /etc/NetworkManager/NetworkManager.conf:

Code: Select all
[main]
no-auto-default=08:9E:01:DD:DB:04,


Nothing else, looks pretty frugal, to say the least.

Here is my /etc/resolv.conf:

Code: Select all
# Generated by resolvconf
domain zedat.fu-berlin.de
nameserver 160.45.8.8
nameserver 160.45.10.12
nameserver 130.133.1.57


Can't remember whether I installed my system at home or here at the university.


Now I ran dhcpd in the terminal:

Code: Select all
# dhcpd
Internet Systems Consortium DHCP Server 4.2.5-P1 Gentoo-r2
Copyright 2004-2013 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
Not searching LDAP since ldap-server, ldap-port and ldap-base-dn were not specified in the config file
Wrote 0 leases to leases file.

No subnet declaration for wlan0 (10.242.124.3).
** Ignoring requests on wlan0.  If this is not what
   you want, please write a subnet declaration
   in your dhcpd.conf file for the network segment
   to which interface wlan0 is attached. **


No subnet declaration for eth0 (172.24.99.6).
** Ignoring requests on eth0.  If this is not what
   you want, please write a subnet declaration
   in your dhcpd.conf file for the network segment
   to which interface eth0 is attached. **


Not configured to listen on any interfaces!

This version of ISC DHCP is based on the release available
on ftp.isc.org.  Features have been added and other changes
have been made to the base software release in order to make                                                                                                               
it work better with this distribution.

Please report for this software via the Gentoo Bugzilla site:
    http://bugs.gentoo.org/

exiting


This for the time being, I feel like leaving things alone, according to the bonmot "Never change a running system"
Je me regarde pour me désoler,
je me compare pour me consoler

Maurice de Talleyrand
Honeyman
Growing Hen
 
Posts: 159
Joined: Sun Apr 08, 2012 2:25
Location: Berlin, Germany

Re: No wired network connection but wireless

Postby Fitzcarraldo » Thu Jun 26, 2014 3:14

Glad to read it is working at present. As I wrote previously, you may find things work even better when SL moves to the latest version of dhcpcd.
User avatar
Fitzcarraldo
Sagely Hen
 
Posts: 7978
Joined: Sat Mar 10, 2007 5:40
Location: United Kingdom

Re: No wired network connection but wireless

Postby Honeyman » Thu Jun 26, 2014 12:19

For the time being things work, so I'm fine right now, but I have found dead sure way to get an IP address via the wired interface. Leaving wireless turned on, receiving an IP over the wifi, then turning it off. Still, that somehow feels like a not so quick and rather dirty workaround.
Je me regarde pour me désoler,
je me compare pour me consoler

Maurice de Talleyrand
Honeyman
Growing Hen
 
Posts: 159
Joined: Sun Apr 08, 2012 2:25
Location: Berlin, Germany


Return to Networking and Wireless

Who is online

Users browsing this forum: No registered users and 1 guest