FC2 eth0 oddness

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dishawjp
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FC2 eth0 oddness

Post by dishawjp » Tue Mar 15, 2005 4:51 pm

Hi All,

Well, I wrote here a few days back that I needed to hose my machine because it had been running too well for too long, and all I really had to do was look around for a problem :-)

My main computer is a dual boot FC2/FC3 machine. A while back I had some really serious issues with FC3, probably related to a combination of running SELinux (which I still insist on running) and bad mixing of apt repositories. Anyway, I reinstalled and FC3 was fine. During the install I had hosed grub and lost my FC2 bootloader and just got around to fixing that last night. Now it dual boots perfectly. But I do now have a problem with FC2. I can't get DHCP information on eth0, but only with FC2. It works fine with FC3 and the same setup used to work fine in FC2. The only change I made to FC2 was to delete a single line in its /etc/fstab that was pointing to a nonexistant swap partition I used to have on the hard drive that FC3 is installed on. Grub is installed (now) on hdc which is the hard drive that FC3 is installed on, so I didn't even mess with that.

When I first boot to FC2, if ifconfig looks like this:

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[dishawjp@eunix dishawjp]$ /sbin/ifconfig
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:16436  Metric:1
          RX packets:246 errors:0 dropped:0 overruns:0 frame:0
          TX packets:246 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:16994 (16.5 Kb)  TX bytes:16994 (16.5 Kb)

[dishawjp@eunix dishawjp]$
Which is exactly what I want. I want both interfaces (eth0 and ppp0) to be user controlled. I have the command "/sbin/ifup eth0" aliased to "net" and when I give that command, I get this:

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[dishawjp@eunix dishawjp]$ net

Determining IP information for eth0... failed.
[dishawjp@eunix dishawjp]$
But then checking my ifconfig, I get this:

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[dishawjp@eunix dishawjp]$ /sbin/ifconfig
eth0      Link encap:Ethernet  HWaddr 02:00:06:E3:3E:9C
          inet6 addr: fe80::6ff:fee3:3e9c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:5273 errors:1 dropped:0 overruns:0 frame:0
          TX packets:6 errors:4 dropped:0 overruns:0 carrier:4
          collisions:0 txqueuelen:1000
          RX bytes:316380 (308.9 Kb)  TX bytes:1508 (1.4 Kb)
          Interrupt:11 Base address:0xef00

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:16436  Metric:1
          RX packets:248 errors:0 dropped:0 overruns:0 frame:0
          TX packets:248 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:17098 (16.6 Kb)  TX bytes:17098 (16.6 Kb)

[dishawjp@eunix dishawjp]$
But if I try to ping yahoo, I get:

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[dishawjp@eunix network-scripts]$ ping http://www.yahoo.com
ping: unknown host http://www.yahoo.com
[dishawjp@eunix network-scripts]$
Which more or less proves that I didn't get any DHCP info from my ISP.

Looking at my ifcfg-eth0 I find:

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[dishawjp@eunix network-scripts]$ more ifcfg-eth0
# Lite-On|LNE100TX
DEVICE=eth0
BOOTPROTO=dhcp
HWADDR=02:00:06:e3:3e:9c
ONBOOT=no
TYPE=Ethernet
USERCTL=yes
PEERDNS=yes
IPV6INIT=yes
[dishawjp@eunix network-scripts]$
Which is very different from my ifcfg-eth0 on FC3 which is:

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[dishawjp@eunix ~]$ more /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=dhcp
ONBOOT=no
TYPE=Ethernet
USERCTL=yes
[dishawjp@eunix ~]$
So one option would be to just comment out the IPV6INIT, PEERDNS, and HWADDR lines from my FC2 ifcfg-eth0, so it would look like the FC3 one, but it used to work, so why should it not work now? Or is that just barking up the wrong tree and should I be looking at something else?

This is no emergency. FC3 is working fine, but it is a puzzle. Thanks for any insight.

Jim Dishaw

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Post by Void Main » Tue Mar 15, 2005 5:42 pm

Did you enable the firewall? You may be blocking DHCP requests on FC2. Try temporarily stopping iptables and then try bringing up your interface again:

# service stop iptables
# ifup eth0

If it still doesn't work look at your messages and boot logs for error messages related to dhcp (dhclient, dhcp, etc). Also I assume the appropriate kernel module is loading based on what is in /etc/modules.conf or /etc/modprobe.conf.

dishawjp
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Post by dishawjp » Tue Mar 15, 2005 8:19 pm

Thanks Voidmain,

I did shut down iptables and try again, though there was no joy. My /etc/modprobe.conf is loading the tulip driver for eth0, so I guess that should be OK, at least it's the same as in FC3. SInce I have to reboot between FC3 (to get onto the 'net) and FC2 to troubleshoot, I forgot to check for error messages in the logfiles, but will take another go at it tomorrow.

You don't think that the differences in the ifcfg-eth0 are worth chasing down?

Anyway, thanks for the suggestions. This will give me something to try and track down tomorrow.

Jim

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Post by Void Main » Wed Mar 16, 2005 6:40 am

There is nothing in your interface configs that should be causing a problem. As far as looking at your logs all you have to do is mount your FC2 root partition in FC3 and go look at them. You don't have to reboot to do that.

dishawjp
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Post by dishawjp » Sat Mar 19, 2005 9:27 pm

Hi All,

I finally got around to playing with this some more. I've googled this and have found several others with similar problems getting DHCP offers, but none with solutions that were of any help to me. I checked out my /etc/resolv.conf file, rechecked all me settings in "system-config-network" and found that the probelm affects my ppp0 connection as well as my eth0 interface.

I did get the following errors from my /var/log/messages file:

for ppp0:

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Mar 19 21:34:30 eunix ifup-ppp: pppd started for ppp0 on /dev/modem at 115200
Mar 19 21:34:30 eunix kernel: CSLIP: code copyright 1989 Regents of the University of California
Mar 19 21:34:30 eunix kernel: PPP generic driver version 2.4.2
Mar 19 21:34:30 eunix pppd[2470]: pppd 2.4.2 started by root, uid 0
Mar 19 21:34:31 eunix wvdial[2492]: WvDial: Internet dialer version 1.53
Mar 19 21:34:31 eunix wvdial[2492]: Initializing modem.
Mar 19 21:34:32 eunix wvdial[2492]: Sending: ATZ
Mar 19 21:34:32 eunix wvdial[2492]: ATZ
Mar 19 21:34:32 eunix wvdial[2492]: OK
Mar 19 21:34:32 eunix wvdial[2492]: Sending: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Mar 19 21:34:32 eunix wvdial[2492]: ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Mar 19 21:34:32 eunix wvdial[2492]: OK
Mar 19 21:34:32 eunix wvdial[2492]: Sending: ATM1L2
Mar 19 21:34:32 eunix wvdial[2492]: ATM1L2
Mar 19 21:34:32 eunix wvdial[2492]: OK
Mar 19 21:34:32 eunix wvdial[2492]: Modem initialized.
Mar 19 21:34:32 eunix wvdial[2492]: Sending: ATDT5795300
Mar 19 21:34:32 eunix wvdial[2492]: Waiting for carrier.
Mar 19 21:34:32 eunix wvdial[2492]: ATDT5795300
Mar 19 21:35:01 eunix wvdial[2492]: CONNECT 48000/ARQ/V90/LAPM/V42BIS
Mar 19 21:35:01 eunix wvdial[2492]: Carrier detected.  Waiting for prompt.
Mar 19 21:35:03 eunix wvdial[2492]: NO CARRIER
Mar 19 21:35:13 eunix wvdial[2492]: Don't know what to do!  Starting pppd and hoping for the best.
Mar 19 21:35:13 eunix pppd[2470]: Serial connection established.
Mar 19 21:35:13 eunix pppd[2470]: Using interface ppp0
Mar 19 21:35:13 eunix pppd[2470]: Connect: ppp0 <--> /dev/modem
Mar 19 21:35:14 eunix pppd[2470]: Serial line is looped back.
Mar 19 21:35:14 eunix pppd[2470]: Connection terminated.
Mar 19 21:35:15 eunix pppd[2470]: Exit.
and for eth0:

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Mar 19 21:37:04 eunix dhclient: sit0: unknown hardware address type 776
Mar 19 21:37:05 eunix dhclient: sit0: unknown hardware address type 776
Mar 19 21:37:07 eunix kernel: eth0: Setting full-duplex based on MII#1 link partner capability of 45e1.
Mar 19 21:37:08 eunix dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
Mar 19 21:37:16 eunix dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 16
Mar 19 21:37:32 eunix dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 13
Mar 19 21:37:45 eunix dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 12
Mar 19 21:37:57 eunix dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7
Mar 19 21:38:04 eunix dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 5
Mar 19 21:38:09 eunix dhclient: No DHCPOFFERS received.
Everything is set to use DHCP, all the hardware works just fine when I boot to FC3, it all used to work with FC2, and I'm stumped.

Any help appreciated.

Jim

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