Re: Internet sharing over multiple interfaces

[Dan Williams <dcbw redhat com>]

On Thu, 2010-05-27 at 16:04 +0200, lutz wrote:
> Hi,
> 
> the power adapter of my router broke and atm I am using NetworkManager
> to create a Internet connection and share it with other PCs. The network
> setup is, that all devices (including the ADSL-modem) are connected to
> an Ethernet switch.
> 
> The computer, which is managing the Internet connection got two wired
> network interfaces eth0 and eth1. eth1 is used to create the ppp0
> connection and was at the beginning the only card, which is connected to
> the switch. I activated "Shared to other computers" in the IPv4-tab of
> both cards, but only with eth1 this seems to work. So i had to use
> another Ethernet cable for connecting eth1 with the switch, too.
> Initially I wanted to use eth0 for my notebook.

Make sure in the connection editor you paste in the MAC address of the
card for each one, otherwise the connection settings might be applied
randomly to each of the two ethernet devices. If you "lock" the
connection to a specific MAC address, NM will only apply those settings
to that specific piece of hardware.

> I am using Debian Sid AMD64 together with NetworkManager 0.8 and
> dnsmasq-base at version 2.52.
> 
> Here is what ifconfig tells me about the interfaces eth0 and eth1:
> $ ifconfig 
> eth0      Link encap:Ethernet  Hardware Adresse 00:22:15:81:5a:c5  
>           inet Adresse:10.42.43.1  Bcast:10.42.43.255
> Maske:255.255.255.0
>           inet6-Adresse: fe80::222:15ff:fe81:5ac5/64
> Gültigkeitsbereich:Verbindung
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metrik:1
>           RX packets:49966 errors:0 dropped:134 overruns:0 frame:0
>           TX packets:61232 errors:0 dropped:0 overruns:0 carrier:0
>           Kollisionen:0 Sendewarteschlangenlänge:1000 
>           RX bytes:5844382 (5.5 MiB)  TX bytes:74125324 (70.6 MiB)
>           Interrupt:17 
> 
> eth1      Link encap:Ethernet  Hardware Adresse 00:22:15:81:78:1a  
>           inet6-Adresse: fe80::222:15ff:fe81:781a/64
> Gültigkeitsbereich:Verbindung
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metrik:1
>           RX packets:205201 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:92754 errors:0 dropped:0 overruns:0 carrier:0
>           Kollisionen:0 Sendewarteschlangenlänge:1000 
>           RX bytes:239220870 (228.1 MiB)  TX bytes:11124327 (10.6 MiB)
>           Interrupt:18

If you're are already locking the connections, let me know and we can
debug further.

Dan