Network Bonding with Ubuntu, combine multiple internet connections

 Bonding network interfaces allows you to enhance your network services by allowing you.

To create fault-tolerance, increase network availability through load balancing, or increase your server’s network bandwidth.

 

Prerequisites

1. Two or more network interface cards.
2. The MAC address (Hardware Address) of each network interface card. This can be found printed on the physical card or in a virtual server’s network hardware settings.
3. All interfaces connected to the same network.
4. An 802.3ad capable switch (for more advanced bonding only).

Lab Server Configuration

To make it easier for you to follow along, our server will have the following configurations.

Network Interface	Interface Name	MAC Address
NIC #1	eth0	00:0c:29:58:65:cc
NIC #2	eth1	00:0c:29:58:65:d6

And when the network bond is created, the server will be assigned the following network settings:

IP Address	Subnet	Gateway	DNS Server
172.30.0.77	255.255.255.0	172.30.0.1	172.30.0.5

Enabling NIC Bonding

1. Out of the box, Ubuntu will not be able to bond network interfaces. You need to install the bonding kernel module by installing the ifenslave package.
    apt-get install ifenslave
2. To enable the newly installed module, stop the network service.
   /etc/init.d/networking stop
3. Now enable the bonding kernel module.
   sudo modprobe bonding

Creating the Network Interfaces

1. Open the network interface configuration file into a text editor, like VI.
      vi /etc/network/interfaces
2. To create a fault-tolerance bond, which we’ll call bond0, that uses interface 1 (eth0) and interface 2 (eth1) add the following lines.

   # Network bond for eth0 and eth1
   auto bond0
   iface bond0 inet static
   address 172.30.0.77
   netmask 255.255.255.0
   gateway 172.30.0.1
   bond-mode 1
   bond-miimon 100
   slaves eth0 eth1

3. Add the following lines to configure interface 1 (eth0) as a slave for bond0. It’s very important to assign the interface the MAC address of the NIC you expect it to use. Without, you may not know which NIC the interface eth0 is assigned to, which is crucial when doing maintenance.

   # eth0 - the first network interface
   auto eth0
   iface eth0 inet manual
   hwaddress ether 00:0c:29:58:65:cc
   bond-master bond0

4. Add the following lines to configure interface 2 (eth1) as a slave for bond0. Just as we did for eth0, remember to add the MAC address.

   # eth1 - the second network interface
   auto eth1
   iface eth1 inet manual
   hwaddress ether 00:0c:29:58:65:d6
   bond-master bond0

5. The configuration file should now look similar to the following example. Remember to modify the highlighted values to match your environment.

   # 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 first network bond
   auto bond0
   iface bond0 inet static
   address 172.30.0.77
   netmask 255.255.255.0
   gateway 172.30.0.1
   bond-mode 1
   bond-miimon 100
   slaves eth0 eth1
   
   #eth0 - the first network interface
   auto eth0
   iface eth0 inet manual
   hwaddress ether 00:0c:29:58:65:cc
   bond-master bond0
   
   #eth1 - the second network interface
   auto eth1
   iface eth1 inet manual
   hwaddress ether 00:0c:29:58:65:d6
   bond-master bond0
   

6. Save your changes and exit the text editor.
7. Bring the network services back online.
    start networking

Validating the Connection

Now that the bond is created we need to test it to ensure it is functioning properly.

1. Run the following command to check the bond.
   cat /proc/network/bonding/bond0
2. If successful, the output should look similar to this:
   

   Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)
   
   Bonding Mode: fault-tolerance (active-backup)
   Primary Slave: None
   Currently Active Slave: eth1
   MII Status: up
   MII Polling Interval (ms): 100
   Up Delay (ms): 0
   Down Delay (ms): 0
   
   Slave Interface: eth1
   MII Status: up
   Speed: 1000 Mbps
   Duplex: full
   Link Failure Count: 0
   Permanent HW addr: 00:0c:29:58:65:d6
   Slave queue ID: 0
   
   Slave Interface: eth0
   MII Status: up
   Speed: 1000 Mbps
   Duplex: full
   Link Failure Count: 0
   Permanent HW addr: 00:0c:29:58:65:cc
   Slave queue ID: 0
   

3. Now ping another network node or the local gateway to test connectivity. I’ll use the gateway IP mentioned earlier as an example.
   ping 172.30.0.1
4. If successful, you should see the following output: :

   PING 172.30.0.1 (172.30.0.1) 56(84) bytes of data.
   64 bytes from 172.30.0.1: icmp_req=1 ttl=64 time=0.340 ms
   64 bytes from 172.30.0.1: icmp_req=2 ttl=64 time=0.194 ms
   64 bytes from 172.30.0.1: icmp_req=3 ttl=64 time=0.153 ms
   64 bytes from 172.30.0.1: icmp_req=4 ttl=64 time=0.343 ms
   64 bytes from 172.30.0.1: icmp_req=5 ttl=64 time=0.488 ms
   
   --- 172.30.0.1 ping statistics ---
   5 packets transmitted, 5 received, 0% packet loss, time 3998ms
   rtt min/avg/max/mdev = 0.153/0.303/0.488/0.121 ms