DHCP on wired interface only sometimes working, always working on wireless interface

PasBern · 06-22-2014, 02:11 PM

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.

I'm on Sabayon, which is a Gentoo-derivative.

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:

# 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:

# dhclient eth0

Here is the status of network manager:

Code:

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:

# systemctl stop NetworkManager

Then:

Code:

# 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:

[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.

Here is my configuration file for network connections

/etc/conf.d/net:

Code:

# This blank configuration will automatically use DHCP for any net.*
# scripts in /etc/init.d.  To create a more complete configuration,
# please review /usr/share/doc/openrc/net.example and save your configuration
# in /etc/conf.d/net (this file :]!).

# The network scripts are now part of net-misc/netifrc
# In order to avoid sys-apps/openrc-0.12.4 from removing this file, this comment was
# added; you can safely remove this comment.  Please see
# /usr/share/doc/netifrc*/README* for more information.
dhcp_wlan0="nosendhost"
dns_domain_wlan0="localdomain"
nis_domain_wlan0="localdomain"
dhcp_eth0="nosendhost"
dns_domain_eth0="localdomain"
nis_domain_eth0="localdomain"

Thanks for your help and tell me, if some important information is still missing. Somehow I have trouble getting a dhcp release on the eth0 interface.

dijetlo · 06-24-2014, 10:02 AM

Quote:

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)

Eth0 is only polling an ipv6 address.

Quote:

[ipv6]
method=ignore

Your network manager has been set to ignore it.
Perhaps if you changed that setting to "auto" or had eth0 poll an ipv4 address instead of ipv6 your issue would go away.

PasBern · 06-25-2014, 03:59 AM

The funny thing, that since I posted my problem here, the issue has not re-occured. Thanks for your help, but for the time being I will leave my settings alone, following the rule "Never change a running system". Since neither at home nor here at the university do I have the possibility to get an IPv6-address, I'm not sure whether having dhcpd polling for such a network address would really make things better, but I do not mean to second-guess you.

dijetlo · 06-25-2014, 06:48 AM

Bitter experience has taught me, Pas, there is nothing wrong with second guessing me.
If sometimes I come across as a "know it all", my apologies. I try to help out this site by working on it's " 0 reply + 24 hours" list so I can seem impersonal but I can assure you that I'm not infallible and do not entertain any fantasies to the contrary.
It does seem odd though, doesn't it? IPV6 is up but the DHCP server is set to ignore. I like your running system rule but I do love a good puzzle.
Post back if it blows up (not that I'm hoping that's going to happen... honest... really... I'm not...honest)

PasBern · 06-26-2014, 06:21 AM

First of all, thanks for your help. Posting a problem and not getting a single response can make one feel left alone in the dark. Hopefully things keep working, so I do not have to come back and ask for further help.

jefro · 06-26-2014, 02:36 PM

It was nice of dijetlo to try to offer help and seemingly an appropriate reply. It's hard to try to guess issues miles away.