2 ethernet cards config

jonfa · 05-25-2001, 08:32 PM

Hi all,

I have 2 ethernet cards that are identical on my redhat 6.2 box. eth0 is connected to a router and it works fine. How do I get linux to:

1. see my second card (eth1) on boot up?
2. see if the second one works ok?

I can see the eth0 and eth1 in /etc/conf.modules, but not in /etc/sysconfig/network-scripts/ directory. All that is here is ifcfg-eth0.

Thanks.

Jon

jonfa · 05-25-2001, 08:48 PM

ok, I setup eth1 in linuxconf and gace it a different IP address from eth0. I then pinged eth1's IP address and it worked. I then pinged eth0's IP address and it too worked. Does this mean that they are both configured properly? If so, why don't I see eth1 loaded on boot up like I do eth0?

Thanks,

Jon

gboutwel · 05-25-2001, 10:10 PM

Quote:

Originally posted by jonfa
ok, I setup eth1 in linuxconf and gace it a different IP address from eth0. I then pinged eth1's IP address and it worked. I then pinged eth0's IP address and it too worked. Does this mean that they are both configured properly? If so, why don't I see eth1 loaded on boot up like I do eth0?

Hmm... I configured them using Linuxconf the same way...
I tested mine with ping eth0 and ping eth1, you could also try:

ping eth0 eth1 (which tells ping to use eth1 as a 'gateway' for the ping to eth0) and
ping eth1 eth0 (which,would do the reverse of the other ping)

If those all check out, then you should be ok. The only other checks/pings to do would be to ping out to machines on the network(s) connected to those NICs.

HTH,

George

P.S. I can't get at my machine that has two NICs right now, but when I can I'll post what my sysconfig directory looks like...

jonfa · 05-25-2001, 10:23 PM

Hey,

I managed to get eth0 and eth1 to show on booy up. I can ping ok using both of them. However, if I say
"ping eth0 eth1" I get a "unknown host eth0" response.

Jon

jonfa · 05-25-2001, 10:31 PM

never mind my last post. Everything is ok.
i realized i neede the IP numbers and not the literal eth#'s.
thanks.

gboutwel · 05-27-2001, 01:30 PM

Quote:

Originally posted by jonfa
never mind my last post. Everything is ok.

i realized i neede the IP numbers and not the literal eth#'s.

thanks.

. Glad you got everything working... Yeah after reading back over my post I thought I should have mentioned that you wanted to use the IPs associated with the ethx instead of the device name... Oh well, maybe next time...

Glad I could help and enjoy,

smite · 11-10-2003, 01:05 PM

if i have a computer running linux with 2 ethernet cards, and a seperate IP for each, how does that work with web hosting? if i want to add a site, do i need to add an entry for both ifcfg-eth0:x and ifcfg-eth1:x in order for fail-over to occur if one of the ethernet cards were to die?

has anybody messed around with this?

thanks smart people,
matt

inode100 · 11-10-2003, 04:06 PM

I dont know exactly how to do this in Linux, but i expect that the principle is the same as as with Unix. Basically i think you need some software that allows for the failover.. how this works is that you have an IP associated with each ethx as usual, but have a virtual floating IP address that will "float" across to eth2 from eth1 if eth1 was to break. What the software does is effectively monitor the NIC's and provides the ability to have the virtual IP. Your webserver, eg Apache will use the virtual IP and will think it is just like any other IP. There are a few different versions of this basic idea in Unix world.. i'm betting same/similar thing exists in Linux world... best to have a google...eg, i found this on my first search "IP multipathing on Linux"

http://lists.linux-ha.org/pipermail/...ay/004753.html

Let me know how you get on...

Inode