How to establish two ethernet connections simultaneously?

Question

Hi!
I have a two-ports router. The first port via ordinary RG-45, and the second port via usb interface.
I want to have both of them to be connected simultaneously. I done this at Gentoo, but can't to do at Arch.
So, what I done exactly:
I found and loaded usbnet module: modprobe usbnet. After that I written appropriate values for new interface (eth1) in /etc/conf.d/network
interface=eth0
address=192.168.1.7
netmask=255.255.255.0
broadcast=192.168.1.255
gateway=192.168.1.1
interface=eth1
address=192.168.1.70
netmask=255.255.255.0
broadcast=192.168.1.255
gateway=192.168.1.1
At this point I restarted networking: systemctl stop/start network and checked for new interface:
ip addr | sed '/^[0-9]/!d;s/: <.*$//'
and got output:
1. lo
2. eth0
3. eth1
OK, I decided to test new interface:
ip link set eth0 down
ip link set eth1 up
eth1 started succesfully. But I can't to start eth0 back: 'ip link set eth0 up' does nothing, even I stopping eth1
I tried to reboot and checked eth0 again: eth0 gone. No more eth0...
ip addr | sed '/^[0-9]/!d;s/: <.*$//'
1. lo
3. eth1
Second interface that was eth0 is missing. And I can't get it back.
Where is eth0 and how to connect both interfaces simultaneously?
Thanks in advance for any help.
Last edited by chord (2012-11-14 21:35:07)

Answer 1

fukawi2 wrote:
hunterthomson wrote:No, using a bridge device connecting two Hosts to your Arch router/switch will not cause a loop.
I'm assuming the "two devices" are actually the 1 router (via Cat5 and USB), and that the router is also acting as a bridge between those 2 interfaces.
That's my understanding of the OP's situation anyway.
That will not cause a switching loop. STP is enabled by defualt on a bridge device and will take care of that. The packets will only use one inteface, until one link is down. Then the packets will use the other interface.
EDIT: Hum, really the OP didn't really give us enough info.
The way I read it was that the Arch computer is a Router with 2 interfaces 1 RJ-45 and one USB-to-RJ-45. Then that's it. He didn't say anything more about his network. So, origonaly thought that he must be wanting to connect to other computer to this "Arch Router"
|----------------------|
|    Arch                |
|   ____#-B___      |
|--/--------------\----|
|--#1----------#2---|
    |                 |
    |                 |
|--#--|        |--#--|
| H1  |        |  H2 |
|------|        |------|
BUT, This 'could' cause a broadcast storm if the "Switch GW" didn't suport STP.
|----------------------|
|    Arch                |
|   ____#-B___      |
|--/--------------\----|
|--#1----------#2---|
    |                 |
    |                 |
|--#---#---#--#---|
|  Switch GW         |
|----------------------|
Last edited by hunterthomson (2012-11-19 08:39:22)