Re: [gentoo-user] HELP! Network status changes randomly, how to diagnose?

[Erik]

Erik wrote:
> Frank Jahn wrote:
>> Erik schrieb:
>>> I am trying to connect my Gentoo computer to my D-Link DVG-1120 (VoIP
>>> Gateway with NAT) again after 3 months. It used to work great, but now
>>> the network status is changing randomly. Sometimes I can load a
>>> webpage,
>>> but then when I click on a link I get an error message. Then it may
>>> suddenly work again. The Internet connection to the gateway works fine
>>> and I can make phonecalls with the phones that are connected to it. It
>>> is the link to the computer that is broken. The computer works when
>>> connected directly to the internet and the cable works perfectly too
>>> (tested elsewhere). I see that it is changing randomly by executing the
>>> command
>>>    ifconfig eth0|grep "inet addr:"
>>> repeateldy. Sometimes I get nothing, sometimes I get:
>>>          inet addr:192.168.0.46  Bcast:192.168.0.255
>>> Mask:255.255.255.0
>>> It looks random. What can I do about it? Is there some software for
>>> analyzing it?
>> could you post your config please?
> Thanks for your answer. Here is some configuration:
> =================================================
> # cat /etc/modules.autoload.d/kernel-2.6|grep -E "(b44|ipw2100)"
> b44
> ipw2100
> # lsmod|grep -E "(b44|ipw2100)"
> b44                    18636  0
> ipw2100                71028  0
> ieee80211              26184  1 ipw2100
> firmware_class          6976  1 ipw2100
> # cat /etc/modules.d/b44
> alias eth0 b44
> # cat /etc/modules.d/ipw2100
> alias eth1 ipw2100
> # ls -l /etc/conf.d/net* /etc/init.d/net*
> -rw-r--r-- 1 root root 32176 28 aug 20.43 /etc/conf.d/net.example
> lrwxrwxrwx 1 root root     6 28 aug 20.43 /etc/init.d/net.eth0 -> net.lo
> lrwxrwxrwx 1 root root     6 18 feb  2006 /etc/init.d/net.eth1 -> net.lo
> -rwxr-xr-x 1 root root 30045 28 aug 20.43 /etc/init.d/net.lo
> -rwxr-xr-x 1 root root  3046 28 aug 20.43 /etc/init.d/netmount
> # ps aux|grep -E "(ifplug|dhcp|eth)"
> root      1010  0.0  0.0   1472   428 ?        Ss   16:27   0:00
> /usr/sbin/ifplugd --iface=eth0
> root      1530  0.0  0.0   1600   228 ?        Ss   16:28   0:00
> /sbin/dhcpcd -h c213-100-41-30.swipnet.se eth0
> root      1980  0.0  0.0   1780   652 pts/1    R+   17:03   0:00 grep
> -E (ifplug|dhcp|eth)
> # rc-update show
>               acpid |      default
>           alsasound |      default
>            bootmisc | boot
>             checkfs | boot
>           checkroot | boot
>               clock | boot
>         consolefont | boot
>             cpufreq | boot
>                 gpm | boot
>              hdparm | boot
>            hostname | boot
>             hotplug | boot
>             kbdrate | boot
>             keymaps | boot
>               local |      default nonetwork
>          localmount | boot
>             modules | boot
>              net.lo | boot
>            netmount |      default
>             postfix |      default
>               power |      default
>           rmnologin | boot
>           syslog-ng |      default
>             urandom | boot
>                 xdm |      default
> # emerge -pv baselayout net-tools iproute2
>
> These are the packages that would be merged, in order:
>
> Calculating dependencies... done!
> [ebuild   R   ] sys-apps/baselayout-1.12.4-r7  USE="unicode -bootstrap
> -build -static" 0 kB
> [ebuild   R   ] sys-apps/net-tools-1.60-r11  USE="nls -static" 0 kB
> [ebuild   R   ] sys-apps/iproute2-2.6.15.20060110  USE="berkdb -atm
> -minimal" 0 kB
>
> Total size of downloads: 0 kB
> =================================================
>
>
> What does this mean?:
> # /etc/init.d/net.eth0 start
> * Service net.eth0 starting
> * WARNING:  net.eth0 has started but is inactive
>
> I made this script to test how often it fails. It checks ifconfig 10
> 000 times and reports how many times it did NOT have an address:
> #! /bin/bash
> export I=0
> export FAILURES=0
> while test $I -lt 10000; do
>    export I=$(dc -e "$I 1 + p");
>    export FAILURES=$(dc -e "$FAILURES $(ifconfig eth0|grep "inet
> addr:">/dev/null; echo $?) + p");
>    done
> echo FAILURES=$FAILURES
>
>
> When I run it I get:
> FAILURES=9786
> FAILURES=9787
> FAILURES=9779
> (numbers vary somewhat between runs)
>
> Running the script with the computer connected directly to the
> Internet gives:
> FAILURES=0
>
> What else should I do?
I have narrowed down the problem further. I am now connected with a 
static IP address and it works just fine.

# grep "^[^#]" /etc/conf.d/net.eth0
config_eth0=( "192.168.0.16 netmask 255.255.255.0 broadcast 192.168.0.255" )
routes_eth0=(
        "default via 192.168.0.1"               # IPv4 default route
)


So I guess it must be the DHCP client on the computer that fails somehow.
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