Bridge Networking in RHEL

Have you ever deal with servers that have many lan card??. Have you ever wanted to optimize the function of these lan cards for failover??. If so, we can use Bridge networking.
With bridged networking we can set many lan card for failover. This means that if one of the lan card does not connect to the network, then the connection will be handled by other active lan card. It also has other benefits that we do not need to memorize which lan card is used and which one is not.

Every operating system has its own way to implement the bridge. In this blog, we will discuss about the bridge networking on Redhat Enterprise Linux (RHEL).
To set the bridge, perform the following steps:

1. login as root
2. shutdown interface that will be bridged
   

   ifdown eth0
   ifdown eth1
   

3. go to /etc/sysconfig/network-scripts
   

   cd /etc/sysconfig/network-scripts
   

4. edit file ifcfg-eth0
   

   vim ifcfg-eth0
   

5. add these codes:
   

   DEVICE=eth0
   HWADDR=00:AA:BB:CC:DD:EE
   ONBOOT=yes
   BRIDGE=bridge0
   

6. edit file ifcfg-eth1
   

   vim ifcfg-eth1
   

7. add these lines:
   

   DEVICE=eth1
   HWADDR=00:AA:BB:CC:DD:FF
   ONBOOT=yes
   BRIDGE=bridge0
   

8. edit file ifcfg-bridge0
   

   vim ifcfg-bridge0
   

9. add these lines:
   

   DEVICE=bridge0
   BOOTPROTO=none
   ONBOOT=yes
   NETMASK=255.255.255.0
   IPADDR=192.168.1.2
   TYPE=Bridge
   USERCTL=no
   IPV6INIT=no
   GATEWAY=192.168.1.1
   DELAY=0
   

10. activate interface
    

    ifup eth0
    ifup eth1
    ifup bridge0
    

11. check network using ifconfig