Can't get eth1 to work, just eth0.

Thrifty · 07-22-2004, 09:13 AM

Got a problem on a SuSe 8.2 box. I'm trying to set it up as a firewall, using Yast's built in firewall feature. So this spare computer should be a hardware firewall. If I understand this correctly, you set up a computer with two ethernet cards. Run a wire from the wall to eth0, then run another from eth1 to your internal network.

I've got one Ethernet card working on this computer, but only one. If I enter ifconfig, I get a readout for the loopback and for eth0. During bootup, the computer initializes eth0 but not eth1. It won't detect the card, and acts as though it doesn't exist.

I entertained the idea that the card was broken, but I tried this same thing inside another machine. SuSe autodetected the card just fine. I even switched the one working card to a different slot on the motherboard. Since it still worked, I know that the slot is fine.

How can I get this thing to work with two network cards? How can I get eth1 to work?

J.W. · 07-23-2004, 05:33 PM

First, let's confirm that the second card is being seen. What are the results of running:

Code:

lspci

This command simply lists what devices are present in the PCI slots. Second, please post the make and model of both cards you're using, and indicate which is eth0 and which is eth1. Another likely issue could be that your eth1 card requires a kernel module that is not being loaded. Please also post the results of running:

Code:

lsmod

That command will list which kernel modules have been loaded, and if we know what NIC you're using, chances are good that someone will know which module is needed to support it.

Finally, have you tried simply bouncing eth1?

Code:

ifconfig eth1 down
ifconfig eth1 up
ifconfig

These commands will bring down the eth1 interface, then bring it back up, then list what interface connections you've got.

Note: the above is not intended to be a solution (although it may resolve the problem) but rather as a useful first step in diagnosing what a few likely issues could be. Good luck with it. -- J.W.

mritch · 07-23-2004, 05:43 PM

you can check if it's recognized by looking at "ifconfig -a". this will show all your interfaces (up or not).
if it's not there add the following kernel parameter to your prompt at bootup:

ether=0,0,eth0 ether=0,0,eth1

..to tell the kernel that there are two cards (be sure both cards are supported).

look at the ethernet-howto.
we need more information. send in relevant lines from the commands J.W. mentioned.

sl mritch.

Thrifty · 07-26-2004, 08:46 AM

Quote:

Originally posted by J.W.
First, let's confirm that the second card is being seen. What are the results of running:

Code:

lspci

00:00.0 Host bridge: VIA Technologies, Inc. VT82C598 [Apollo MVP3] (rev 04)
00:01.0 PCI bridge: VIA Technologies, Inc. VT82C598/694x [Apollo MVP3/Pro133x AGP]
00:07.0 ISA bridge: VIA Technologies, Inc. VT82C586/A/B PCI-to-ISA [Apollo VP] (rev 47)
00:07.1 IDE interface: VIA Technologies, Inc. VT82C586/B/686A/B PIPC Bus Master IDE (rev 06)
00:07.2 USB Controller: VIA Technologies, Inc. USB (rev 02)
00:07.3 Bridge: VIA Technologies, Inc. VT82C586B ACPI (rev 10)
00:0a.0 Ethernet controller: Digital Equipment Corporation DECchip 21140 [FasterNet] (rev 22)
00:0b.0 Ethernet controller: 3Com Corporation 3c905C-TX/TX-M [Tornado] (rev 78)
01:00.0 VGA compatible controller: S3 Inc. Trio 64 3D (rev 01)

This command simply lists what devices are present in the PCI slots. Second, please post the make and model of both cards you're using, and indicate which is eth0 and which is eth1.

Okay.

eth0 --> 3Com 3C905C-TX Fast Etherlink for PC Management NIC
eth1 --> Kingston KNE100TX Fast Ethernet

Also, and I don't know if this is relevant, but they have two different statically assigned IP addresses.

Another likely issue could be that your eth1 card requires a kernel module that is not being loaded. Please also post the results of running:

Code:

lsmod

That command will list which kernel modules have been loaded, and if we know what NIC you're using, chances are good that someone will know which module is needed to support it.

Module Size Used by Not tainted
tulip 40352 1
isa-pnp 29672 0 (unused)
ipv6 134388 -1 (autoclean)
ipt_TCPMSS 2328 1 (autoclean)
ipt_TOS 984 9 (autoclean)
ipt_state 568 50 (autoclean)
ipt_LOG 3288 71 (autoclean)
raw1394 14516 0 (unused)
ieee1394 32880 0 [raw1394]
3c59x 26064 1
ipt_REJECT 2904 3 (autoclean)
iptable_mangle 2072 1 (autoclean)
iptable_filter 1644 1 (autoclean)
ip_nat_ftp 2736 0 (unused)
iptable_nat 15470 1 [ip_nat_ftp]
ip_conntrack_ftp 3664 1
ip_conntrack 16380 3 [ipt_state ip_nat_ftp iptable_nat ip_conntrack_ftp]
ip_tables 11040 10 [ipt_TCPMSS ipt_TOS ipt_state ipt_LOG ipt_REJECT iptable_mangle iptable_filter iptable_nat]
lvm-mod 65412 0 (autoclean)
reiserfs 200532 1

Finally, have you tried simply bouncing eth1?

Code:

ifconfig eth1 down
ifconfig eth1 up
ifconfig

These commands will bring down the eth1 interface, then bring it back up, then list what interface connections you've got.

Tried that. No good. Doesn't an rcnetwork restart accomplish the same goal?

I also want to clarify that ifconfig will show both Ethernet cards (it wouldn't before, but I got that fixed) and both are autodetected. I can ping from eth0 to eth1 and vice versa. I can ping from eth0 to the outside, but I cannot ping from eth1 to the outside.

Note: the above is not intended to be a solution (although it may resolve the problem) but rather as a useful first step in diagnosing what a few likely issues could be. Good luck with it. -- J.W.

Thrifty · 08-02-2004, 01:55 PM

So.... any insights?

jdepaul · 08-03-2004, 02:41 PM

have you verified that ip forwarding is configured in your kernel

Thrifty · 08-03-2004, 02:53 PM

Quote:

Originally posted by jdepaul
have you verified that ip forwarding is configured in your kernel

No I haven't. How might I go about doing that?

jdepaul · 08-03-2004, 03:01 PM

I apologize but I am not familiar with SuSe, however, here is how I would do it in RHEL:

Below is a snippet of my /etc/sysctl. I would set IP forwarding to 1

more /etc/sysctl.conf
# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.

# Controls IP packet forwarding
net.ipv4.ip_forward = 0

Peace
JD