Linux Port Bonding.

AKA port trunking, ...

Good Instructions

Here is a good link, that details how to do this on Ubuntu 7.10 (and 8.04)

http://www.astroshapes.com/information-technology/blog/archives/21-port-bonding-with-linux-ubuntu-server.html

My example

One bond with the two built-in interface on our hp server. (Basically following the above link.)

sudo apt-get install ifenslave

sudo vi /etc/modprobe.d/arch/i386 

my /etc/modprobe.d/arch/i386 file

alias parport_lowlevel parport_pc

alias binfmt-0064 binfmt_aout

alias bond0 bonding
options bond0 mode=balance-alb miimon=100 max_bonds=1

sudo vi /etc/network/interfaces

my /etc/network/interfaces file

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto bond0
#auto eth0

#iface eth0 inet static
#       address 10.2.0.78
#       netmask 255.255.255.0
#       network 10.2.0.0
#       broadcast 10.2.0.255
#       gateway 10.2.0.1
#       # dns-* options are implemented by the resolvconf package, if installed
#       dns-nameservers 10.2.0.54 10.2.1.54
#       dns-search ties2.net

iface bond0 inet static
        address 10.2.0.78
        netmask 255.255.255.0
        network 10.2.0.0
        broadcast 10.2.0.255
        gateway 10.2.0.1
        up /sbin/ifenslave bond0 eth0 eth1
        down /sbin/ifenslave -d bond0 eth0 eth1
        # dns-* options are implemented by the resolvconf package, if installed
        dns-nameservers 10.2.0.54 10.2.1.54
        dns-search ties2.net

Reboot!

This is what the interfaces look like with ifconfig (only one ethernet interface is connected)

user@amachine:~$ ifconfig 
bond0     Link encap:Ethernet  HWaddr 00:18:fe:28:2c:78 
          inet addr:10.2.0.78  Bcast:10.2.0.255  Mask:255.255.255.0
          inet6 addr: fe80::218:feff:fe28:2c78/64 Scope:Link
          UP BROADCAST RUNNING MASTER MULTICAST  MTU:1500  Metric:1
          RX packets:135 errors:0 dropped:0 overruns:0 frame:0
          TX packets:309 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:26520 (25.8 KB)  TX bytes:36585 (35.7 KB)

eth0      Link encap:Ethernet  HWaddr 00:18:fe:28:2c:78 
          UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
          RX packets:135 errors:0 dropped:0 overruns:0 frame:0
          TX packets:309 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:26520 (25.8 KB)  TX bytes:36585 (35.7 KB)
          Interrupt:16 

eth1      Link encap:Ethernet  HWaddr 00:18:fe:28:2c:79 
          UP BROADCAST SLAVE 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:17 

lo        Link encap:Local Loopback 
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:32 errors:0 dropped:0 overruns:0 frame:0
          TX packets:32 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:16373 (15.9 KB)  TX bytes:16373 (15.9 KB)

More Links

See /usr/src/linux-source-2.6.15/Documentation/networking/bonding.txt  or where ever your Linux Kernel Source is.

http://www.howtoforge.com/network_bonding_ubuntu_6.10

http://www.kernel.org/pub/linux/kernel/people/marcelo/linux-2.4/Documentation/networking/bonding.txt

http://www.linuxhorizon.ro/bonding.html