Problem with dual Ethernet network routing and gateways

[Mark Jackson]

On 09/05/13 15:42, Mark Jackson wrote:
> I have a dual Ethernet AM335x board which I'm trying to set up, as follows:-
> 
> $ cat /etc/network/interfaces
> auto lo eth0 eth1
> iface lo inet loopback
> iface eth1 inet static
> address 10.0.101.1
> netmask 255.255.0.0
> gateway 10.0.0.1
> iface eth0 inet static
> address 10.1.101.1
> netmask 255.255.0.0
> 
> $ ifconfig
> eth0      Link encap:Ethernet  HWaddr 00:18:31:93:49:34
>           inet addr:10.1.101.1  Bcast:0.0.0.0  Mask:255.255.0.0
>           UP BROADCAST MULTICAST  MTU:1500  Metric:1
>           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:1000
>           RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
>           Interrupt:56
> 
> eth1      Link encap:Ethernet  HWaddr 00:18:31:93:49:35
>           inet addr:10.0.101.1  Bcast:0.0.0.0  Mask:255.255.0.0
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:2756 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:607 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:1000
>           RX bytes:465648 (454.7 KiB)  TX bytes:168843 (164.8 KiB)
> 
> lo        Link encap:Local Loopback
>           inet addr:127.0.0.1  Mask:255.0.0.0
>           UP LOOPBACK RUNNING  MTU:65536  Metric:1
>           RX packets:50 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:50 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:0
>           RX bytes:4066 (3.9 KiB)  TX bytes:4066 (3.9 KiB)
> 
> But my routing table is:-
> 
> $ route
> Kernel IP routing table
> Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
> default         10.1.0.1        0.0.0.0         UG    0      0        0 eth0
> 10.0.0.0        *               255.255.0.0     U     0      0        0 eth1
> 10.1.0.0        *               255.255.0.0     U     0      0        0 eth0

If I add:-

$ route add default gw 10.0.0.1

... I get a gateway on eth1 and my routing table becomes:-

$ route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         10.0.0.1        0.0.0.0         UG    0      0        0 eth1
default         10.1.0.1        0.0.0.0         UG    0      0        0 eth0
10.0.0.0        *               255.255.0.0     U     0      0        0 eth1
10.1.0.0        *               255.255.0.0     U     0      0        0 eth0

... and then I *can* ping out on eth1.

So for a *dual* Ethernet system, how do I get both default gateway entries using
ifup / ifdown / etc ?

Cheers
Mark J.