(Solved) Intermittant booting problem with LAN

chsims1 · 2010-12-06 18:40:21

Hi,

I have a really annoying problem that is getting more frequent. During boot, there is a problem (sometimes) with the LAN. A network drive can not be found and I can't access the Internet (presumably because the router isn't being seen). I can't see anything obvious in the log files. Network seems to start ok, IP address asigned etc.

Any ideas please?

Last edited by chsims1 (2010-12-14 16:34:25)

ralvez · 2010-12-06 19:48:29

check /etc/resolv.conf when the error happens.
Perhaps it is not set and that's the reason you do not get out to the Internet BUT have an IP address.

R.

chsims1 · 2010-12-11 09:42:22

Sorry for the vague first post. To clarify, I use a static IP address, but I sometimes don't see the router on booting:

root /home/ian #  ping 192.168.2.1
PING 192.168.2.1 (192.168.2.1) 56(84) bytes of data.
From 192.168.2.100 icmp_seq=2 Destination Host Unreachable

If I look at the routes table, then the second line with the default gateway(router) takes ages to appear, but it does eventually show up:

root /home/ian #  route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.2.0          *               255.255.255.0     U      0       0        0   eth0
default           192.168.2.1     0.0.0.0               UG     0       0        0   eth0

I have tried removing the default route & re-adding it again.

Having to post this from windows because it is occurring more & more frequently.

After reading the troubleshooting in the 'network' wiki, I looked at what devices were being found:

root /home/ian #  lspci -v
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 01)  
..
Kernel driver in use: r8169                                                                                   
Kernel modules: r8169

and whether the modules were being loaded correctly:

dmesg | grep r8169
r8169 Gigabit Ethernet driver 2.3LK-NAPI loaded                                                                       
r8169 0000:03:00.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16                                                        
r8169 0000:03:00.0: setting latency timer to 64                                                                       
r8169 0000:03:00.0: irq 41 for MSI/MSI-X                                                                              
r8169 0000:03:00.0: eth1: RTL8168b/8111b at 0xffffc900113a8000, 00:50:8d:9a:76:61, XID 18000000 IRQ 41                
Modules linked in: nls_utf8 cifs fscache nvidia(P) joydev usbhid hid snd_hda_codec_realtek snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss r8169 mii snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_timer snd soundcore snd_page_alloc firewire_ohci firewire_core crc_itu_t tulip i2c_i801 thermal processor button i2c_core uhci_hcd ehci_hcd iTCO_wdt iTCO_vendor_support shpchp usbcore pci_hotplug sg evdev pcspkr intel_agp ext4 mbcache jbd2 crc16 sd_mod sr_mod cdrom pata_acpi ahci pata_jmicron ata_piix libahci floppy libata scsi_mod

Note that dmesg doesn't say that the link is up, which it would normally when working correctly.

So it looks as though the device modules are not being loaded. Why should that be?

Last edited by chsims1 (2010-12-12 08:40:07)

ralvez · 2010-12-11 16:42:55

Well ... looking at your data it seems the module IS recognized and obviously used at times.
The reason a module would not load, most likely, would be that either the module is corrupt (clearly not your case) OR the device is not read when the module is
trying to upload.
In that second case, I would become very suspicious of the device.
Is perhaps faulty? I mean like having a "cold joint"... a term we use in electronics engineering to point to a soldered contact that "looks good" but fails at times because
the inner surface of the joint is not really soldered.

If you have another NIC I would replace the one currently in use and see if things improve... if this is your case, that would be the ONLY reliable way to tell.

Hope this helps.

R.

.:B:. · 2010-12-11 16:43:58

Chsims1, please use [ code ] tags for the command output you posted - it would greatly improve readability of your post.

chsims1 · 2010-12-12 08:35:36

I don't think it can be a physical problem with the NIC, because I found when fiddling that if I run networkmanager (with the problem present) then this assigns me a dynamic IP (from the router ie, suddenly the router is "seen") on eth1 & away I go; everything is great. My static IP setup is for eth0. What is the actual difference here between eth0 & eth1 .... I have only a single onboard NIC (wired).

Well, sorted after a fashion. If I explicitely load the r8169 module in rc.conf, then everything is ok. This is despite the auto-load modules being set. So, problem sorted, but don't know why, which is a little unsatisfactory.

Last edited by chsims1 (2010-12-14 16:32:36)

elastic · 2010-12-14 20:47:20

are there two network cards in your sytem? - so maybe they were mixed before loading the one in modules before udev starts autimatic detection

Arch Wiki: Mixed Up Devices, Sound/Network Cards Changing Order Each Boot

Because udev loads all modules asynchronously, they are initialized in a different order. This can result in devices randomly switching names. For example, with two network cards, you may notice a switching of designations between eth0 and eth1.

Arch Linux provides the advantage of specifying the module load order by listing the modules in the MODULES array in rc.conf. Modules in this array are loaded before udev begins auto-loading, so you have full control over the load order.

chsims1 · 2010-12-15 11:33:38

There is actually a second NIC, which I had completely forgotten about (it was only put in to get it out of the way & keep safe). So perhaps your explanation is correct elastic. Thank you for all the replies.

Arch Linux

#1 2010-12-06 18:40:21

(Solved) Intermittant booting problem with LAN

#2 2010-12-06 19:48:29

Re: (Solved) Intermittant booting problem with LAN

#3 2010-12-11 09:42:22

Re: (Solved) Intermittant booting problem with LAN

#4 2010-12-11 16:42:55

Re: (Solved) Intermittant booting problem with LAN

#5 2010-12-11 16:43:58

Re: (Solved) Intermittant booting problem with LAN

#6 2010-12-12 08:35:36

Re: (Solved) Intermittant booting problem with LAN

#7 2010-12-14 20:47:20

Re: (Solved) Intermittant booting problem with LAN

#8 2010-12-15 11:33:38

Re: (Solved) Intermittant booting problem with LAN

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