How to do the NIC Bonding in RHEL6?

NIC Bonding is nothing but it is a term used to describe a way to increase available bandwidth. When bonded, two NICs appear to be the same physical device and they also have the same MAC address. It is a Linux kernel feature that allows to aggregate multiple like interfaces (such as eth0, eth1) into a single virtual link such as bond0. To to the bonding between eth0 and eth1 we will follow below steps.

BONDING MODES Allows you to specify the bonding policy. The can be one of:

Balance-rr or 0 — Sets a round-robin policy for fault tolerance and load balancing. Transmissions are received and sent out sequentially on each bonded slave interface beginning with the first one available.

Active-backup or 1 — Sets an active-backup policy for fault tolerance. Transmissions are received and sent out via the first available bonded slave interface. Another bonded slave interface is only used if the active bonded slave interface fails.

Balance-xor or 2 — Sets an XOR (exclusive-or) policy for fault tolerance and load balancing. Using this method, the interface matches up the incoming request's MAC address with the MAC address for one of the slave NICs. Once this link is established, transmissions are sent out sequentially beginning with the first available interface.

Broadcast or 3 — Sets a broadcast policy for fault tolerance. All transmissions are sent on all slave interfaces.

802.3ad or 4 — Sets an IEEE 802.3ad dynamic link aggregation policy. Creates aggregation groups that share the same speed and duplex settings. Transmits and receives on all slaves in the active aggregator. Requires a switch that is 802.3ad compliant.

Balance-tlb or 5 — Sets a Transmit Load Balancing (TLB) policy for fault tolerance and load balancing. The outgoing traffic is distributed according to the current load on each slave interface. Incoming traffic is received by the current slave. If the receiving slave fails, another slave takes over the MAC address of the failed slave.

Balance-alb or 6 — Sets an Active Load Balancing (ALB) policy for fault tolerance and load balancing. Includes transmit and receive load balancing for IPV4 traffic. Receive load balancing is achieved through ARP negotiation.

Steps to follow:-

1. Create a bond0 file in /etc/sysconfig/network-script/ by copying ifcfg-eth0 file as given below

#cp  /etc/sysconfig/network-script/ifcfg-eth0  /etc/sysconfig/network-script/ifcfg-bond0   

2. Adjust the bond0 file according to following line:

#vim /etc/sysconfig/network-scripts/ifcfg-bond0

DEVICE=bond0
TYPE=Ethernet
ONBOOT=yes
BOOTPROTO=none
IPADDR=xx.xx.xx.xx
GATEWAY=xx.xx.xx.xx

NETMASK=xx.xx.xx.xx
NAME="System Bond0"

BONDING_OPTS=”mode=1  miimon=100”

3. Modify ifcfg-eth0 files as follows:

# vi /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0
TYPE=Ethernet

ONBOOT=yes
BOOTPROTO=none
NAME="System eth0"

MASTER=bond0

SLAVE=yes

4. Modify ifcfg-eth1 files as follows:

# vi /etc/sysconfig/network-scripts/ifcfg-eth1

DEVICE=eth1
TYPE=Ethernet

ONBOOT=yes
BOOTPROTO=none
NAME="System eth1"

MASTER=bond0

SLAVE=yes

5. Create a file with name of bonding.conf inside /etc/modprobe.d/ folder and write alias bond0 bonding inside that and save the file

6. Now stop the NetworkManager service and do the chkconfig off

#/etc/init.d/NetworkManager stop

#chkconfig NetworkManager off

7. Restart the networking service in order to bring up bond0 interface:

#service network restart

#chkconfig network on

Type the following command to check the current status of bonding:
#cat /proc/net/bonding/bond0

#ifconfig

Sample outputs:

bond0     Link encap:Ethernet  HWaddr 00:0C:29:C6:BE:59
 inet addr:192.168.1.20  Bcast:192.168.1.255  Mask:255.255.255.0
 inet6 addr: fe80::200:ff:fe00:0/64 Scope:Link
 UP BROADCAST RUNNING MASTER MULTICAST  MTU:1500  Metric:1
 RX packets:2804 errors:0 dropped:0 overruns:0 frame:0
 TX packets:1879 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:0
 RX bytes:250825 (244.9 KiB)  TX bytes:244683 (238.9 KiB)

eth0      Link encap:Ethernet  HWaddr 00:0C:29:C6:BE:59
 inet addr:192.168.1.20  Bcast:192.168.1.255  Mask:255.255.255.0
 inet6 addr: fe80::20c:29ff:fec6:be59/64 Scope:Link
 UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
 RX packets:2809 errors:0 dropped:0 overruns:0 frame:0
 TX packets:1390 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1000
 RX bytes:251161 (245.2 KiB)  TX bytes:180289 (176.0 KiB)
 Interrupt:11 Base address:0x1400

eth1      Link encap:Ethernet  HWaddr 00:0C:29:C6:BE:59

 inet addr:192.168.1.20  Bcast:192.168.1.255  Mask:255.255.255.0
 inet6 addr: fe80::20c:29ff:fec6:be59/64 Scope:Link
 UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
 RX packets:4 errors:0 dropped:0 overruns:0 frame:0
 TX packets:502 errors:0 dropped:0 overruns:0 carrier:0
 collisions:0 txqueuelen:1000
 RX bytes:258 (258.0 b)  TX bytes:66516 (64.9 KiB)
 Interrupt:10 Base address:0x1480