NIC Bonding/Teaming in RHEL 6-7/CentOS 6-7

Linux allows administrators to bind multiple network interfaces together into a single channel using the bonding kernel module and a special network interface called a channel bonding interface. Channel bonding enables two or more network interfaces to act as one, simultaneously increasing the bandwidth and providing redundancy. Network Bonding is a kernel feature and also known as NIC teaming. 

Let’s assume we are configuring bond0 with interfaces ifcfg-enp25s0f0 and ifcfg-enp25s0f1

We need to create a channel bonding interface configuration file on /etc/sysconfig/network-scripts/ directory called ifcfg-bond<N> replacing <N> with the number for the interface, such as 0 and specify the bonding parameters on the file. Here we are creating ifcfg-bond0 file with following contents:

# cat ifcfg-bond0

DEVICE=bond0

ONBOOT=yes

BOOTPROTO=static

IPADDR=10.20.10.11

NETMASK=255.255.255.0

GATEWAY=10.20.10.1

BONDING_OPTS="mode=4 miimon=200"

or 

# cat ifcfg-bond1

DEVICE=bond1

TYPE=Ethernet

ONBOOT=yes

BOOTPROTO=static

IPADDR=10.20.10.11

NETMASK=255.255.255.0

GATEWAY=10.20.10.1

MTU=9000

BONDING_OPTS="mode=802.3ad miimon=100 lacp_rate=slow xmit_hash_policy=layer2+3"

Below are the bonding modes:

• mode=0 (Balance Round Robin)
• mode=1 (Active backup)
• mode=2 (Balance XOR)
• mode=3 (Broadcast)
• mode=4 (802.3ad)
• mode=5 (Balance Transmit Load Balance (TLB))
• mode=6 (Balance Adaptive Load Balance (ALB))

After the channel bonding interface is created, the network interfaces to be bound together and configured by adding the MASTER= and SLAVE= directives to their configuration files. Below are the interface files: 

# cat ifcfg-enp25s0f0 
DEVICE=enp25s0f0
TYPE=Ethernet
BOOTPROTO=none
ONBOOT=yes
NM_CONTROLLED=no
IPV6INIT=no
MASTER=bond0 #or bond1
SLAVE=yes


#cat ifcfg-enp25s0f1
DEVICE=enp25s0f1
TYPE=Ethernet
BOOTPROTO=none
ONBOOT=yes
NM_CONTROLLED=no
IPV6INIT=no
MASTER=bond0 #or bond1
SLAVE=yes

Now, load the bond driver, bring up the newly created bond0 or bond1 interface and verify the same by following commands:

# modprobe bonding
# ifconfig bond0 up
# ifconfig

# ip a
# cat /proc/net/bonding/bond0

Cheers :-)